218757321225 has 27 divisors (see below), whose sum is σ = 391831235029. Its totient is φ = 116666829600.

The previous prime is 218757321151. The next prime is 218757321227. The reversal of 218757321225 is 522123757812.

It is a happy number.

The square root of 218757321225 is 467715.

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

218757321225 is a `hidden beast` number, since 21 + 87 + 5 + 7 + 321 + 225 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 107099762121 + 111657559104 = 327261^2 + 334152^2 .

It is not a de Polignac number, because 218757321225 - 2²¹ = 218755224073 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218757321227) 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, 7000135 + ... + 7031315.

Almost surely, 2^218757321225 is an apocalyptic number.

218757321225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

218757321225 is the 467715-th square number.

218757321225 is the 233858-th centered octagonal number.

It is an amenable number.

218757321225 is a deficient number, since it is larger than the sum of its proper divisors (173073913804).

218757321225 is an frugal number, since it uses more digits than its factorization.

218757321225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62378 (or 31189 counting only the distinct ones).

The product of its digits is 470400, while the sum is 45.

The spelling of 218757321225 in words is "two hundred eighteen billion, seven hundred fifty-seven million, three hundred twenty-one thousand, two hundred twenty-five".