216257551225 has 27 divisors (see below), whose sum is σ = 284913407821. Its totient is φ = 162799452800.

The previous prime is 216257551217. The next prime is 216257551249. The reversal of 216257551225 is 522155752612.

It is a happy number.

The square root of 216257551225 is 465035.

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

It can be written as a sum of positive squares in 4 ways, for example, as 5058481129 + 211199070096 = 71123^2 + 459564^2 .

It is not a de Polignac number, because 216257551225 - 2³ = 216257551217 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 39525240 + ... + 39530710.

Almost surely, 2^216257551225 is an apocalyptic number.

216257551225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

216257551225 is the 465035-th square number.

216257551225 is the 232518-th centered octagonal number.

It is an amenable number.

216257551225 is a deficient number, since it is larger than the sum of its proper divisors (68655856596).

216257551225 is an frugal number, since it uses more digits than its factorization.

216257551225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10986 (or 5493 counting only the distinct ones).

The product of its digits is 420000, while the sum is 43.

The spelling of 216257551225 in words is "two hundred sixteen billion, two hundred fifty-seven million, five hundred fifty-one thousand, two hundred twenty-five".