218342144724025 has 27 divisors (see below), whose sum is σ = 314948149858191. Its totient is φ = 149719973177040.

The previous prime is 218342144723981. The next prime is 218342144724029. The reversal of 218342144724025 is 520427441243812.

The square root of 218342144724025 is 14776405.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 78603172100649 + 139738972623376 = 8865843^2 + 11821124^2 .

It is not a de Polignac number, because 218342144724025 - 2¹⁵ = 218342144691257 is a prime.

It is a super-3 number, since 3×218342144724025³ (a number of 44 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 218342144724025.

It is not an unprimeable number, because it can be changed into a prime (218342144724029) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 516963084 + ... + 517385266.

Almost surely, 2^{218342144724025} is an apocalyptic number.

218342144724025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

218342144724025 is the 14776405-th square number.

218342144724025 is the 7388203-rd centered octagonal number.

It is an amenable number.

218342144724025 is a deficient number, since it is larger than the sum of its proper divisors (96606005134166).

218342144724025 is an frugal number, since it uses more digits than its factorization.

218342144724025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844390 (or 422195 counting only the distinct ones).

The product of its (nonzero) digits is 3440640, while the sum is 49.

218342144724025 divided by its sum of digits (49) gives a square (4455962137225 = 2110915²).

Adding to 218342144724025 its reverse (520427441243812), we get a palindrome (738769585967837).

The spelling of 218342144724025 in words is "two hundred eighteen trillion, three hundred forty-two billion, one hundred forty-four million, seven hundred twenty-four thousand, twenty-five".