218981882025 has 45 divisors (see below), whose sum is σ = 405669153351. Its totient is φ = 116779106160.

The previous prime is 218981882023. The next prime is 218981882101. The reversal of 218981882025 is 520288189812.

It is a happy number.

The square root of 218981882025 is 467955.

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., 78833477529 + 140148404496 = 280773^2 + 374364^2 .

It is a tau number, because it is divible by the number of its divisors (45).

It is not a de Polignac number, because 218981882025 - 2¹ = 218981882023 is a prime.

It is a super-2 number, since 2×218981882025² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (218981882023) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 21052776 + ... + 21063174.

Almost surely, 2^218981882025 is an apocalyptic number.

218981882025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

218981882025 is the 467955-th square number.

218981882025 is the 233978-th centered octagonal number.

It is an amenable number.

218981882025 is a deficient number, since it is larger than the sum of its proper divisors (186687271326).

218981882025 is an frugal number, since it uses more digits than its factorization.

218981882025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20820 (or 10407 counting only the distinct ones).

The product of its (nonzero) digits is 1474560, while the sum is 54.

The spelling of 218981882025 in words is "two hundred eighteen billion, nine hundred eighty-one million, eight hundred eighty-two thousand, twenty-five".