866937899025 has 405 divisors, whose sum is σ = 1871917181355. Its totient is φ = 398210709600.

The previous prime is 866937898993. The next prime is 866937899029. The reversal of 866937899025 is 520998739668.

The square root of 866937899025 is 931095.

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

It can be written as a sum of positive squares in only one way, i.e., 312097643649 + 554840255376 = 558657^2 + 744876^2 .

It is a tau number, because it is divible by the number of its divisors (405).

It is not a de Polignac number, because 866937899025 - 2⁵ = 866937898993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (866937899029) by changing a digit.

It is a polite number, since it can be written in 404 ways as a sum of consecutive naturals, for example, 45628310466 + ... + 45628310484.

Almost surely, 2^866937899025 is an apocalyptic number.

866937899025 is the 931095-th square number.

866937899025 is the 465548-th centered octagonal number.

It is an amenable number.

866937899025 is an abundant number, since it is smaller than the sum of its proper divisors (1004979282330).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866937899025 is an frugal number, since it uses more digits than its factorization.

866937899025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 352719360, while the sum is 72.

The spelling of 866937899025 in words is "eight hundred sixty-six billion, nine hundred thirty-seven million, eight hundred ninety-nine thousand, twenty-five".