18511807426225 has 9 divisors (see below), whose sum is σ = 22954667884267. Its totient is φ = 14809428730840.

The previous prime is 18511807426207. The next prime is 18511807426243. The reversal of 18511807426225 is 52262470811581.

The square root of 18511807426225 is 4302535.

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

It is an interprime number because it is at equal distance from previous prime (18511807426207) and next prime (18511807426243).

It can be written as a sum of positive squares in only one way, i.e., 6664250673441 + 11847556752784 = 2581521^2 + 3442028^2 .

It is not a de Polignac number, because 18511807426225 - 2⁵ = 18511807426193 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 21082422 + ... + 21942928.

Almost surely, 2^{18511807426225} is an apocalyptic number.

18511807426225 is the 4302535-th square number.

18511807426225 is the 2151268-th centered octagonal number.

It is an amenable number.

18511807426225 is a deficient number, since it is larger than the sum of its proper divisors (4442860458042).

18511807426225 is an frugal number, since it uses more digits than its factorization.

18511807426225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1721024 (or 860512 counting only the distinct ones).

The product of its (nonzero) digits is 2150400, while the sum is 52.

The spelling of 18511807426225 in words is "eighteen trillion, five hundred eleven billion, eight hundred seven million, four hundred twenty-six thousand, two hundred twenty-five".