218056311225 has 81 divisors (see below), whose sum is σ = 405916184973. Its totient is φ = 116195834880.

The previous prime is 218056311173. The next prime is 218056311349. The reversal of 218056311225 is 522113650812.

The square root of 218056311225 is 466965.

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

218056311225 is a `hidden beast` number, since 2 + 1 + 8 + 0 + 5 + 631 + 12 + 2 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 6084468009 + 211971843216 = 78003^2 + 460404^2 .

It is a tau number, because it is divible by the number of its divisors (81).

It is not a de Polignac number, because 218056311225 - 2⁷ = 218056311097 is a prime.

It is a super-2 number, since 2×218056311225² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 218056311225.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 189120249 + ... + 189121401.

Almost surely, 2^218056311225 is an apocalyptic number.

218056311225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

218056311225 is the 466965-th square number.

218056311225 is the 233483-rd centered octagonal number.

It is an amenable number.

218056311225 is a deficient number, since it is larger than the sum of its proper divisors (187859873748).

218056311225 is an frugal number, since it uses more digits than its factorization.

218056311225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2340 (or 1161 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

Multiplying 218056311225 by its sum of digits (36), we get a square (7850027204100 = 2801790²).

The spelling of 218056311225 in words is "two hundred eighteen billion, fifty-six million, three hundred eleven thousand, two hundred twenty-five".