11997916225 has 27 divisors (see below), whose sum is σ = 15715279593. Its totient is φ = 9085271040.

The previous prime is 11997916219. The next prime is 11997916237. The reversal of 11997916225 is 52261979911.

The square root of 11997916225 is 109535.

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 334780209 + 11663136016 = 18297^2 + 107996^2 .

It is not a de Polignac number, because 11997916225 - 2⁷ = 11997916097 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, 10405249 + ... + 10406401.

Almost surely, 2^11997916225 is an apocalyptic number.

11997916225 is the 109535-th square number.

11997916225 is the 54768-th centered octagonal number.

It is an amenable number.

11997916225 is a deficient number, since it is larger than the sum of its proper divisors (3717363368).

11997916225 is an frugal number, since it uses more digits than its factorization.

11997916225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2354 (or 1177 counting only the distinct ones).

The product of its digits is 612360, while the sum is 52.

The spelling of 11997916225 in words is "eleven billion, nine hundred ninety-seven million, nine hundred sixteen thousand, two hundred twenty-five".