25597957491 has 24 divisors (see below), whose sum is σ = 37889856576. Its totient is φ = 16644141360.

The previous prime is 25597957459. The next prime is 25597957529. The reversal of 25597957491 is 19475979552.

25597957491 is a `hidden beast` number, since 2 + 5 + 5 + 97 + 9 + 57 + 491 = 666.

It is not a de Polignac number, because 25597957491 - 2⁵ = 25597957459 is a prime.

It is a super-2 number, since 2×25597957491² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25597957421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 219556 + ... + 315278.

It is an arithmetic number, because the mean of its divisors is an integer number (1578744024).

Almost surely, 2^25597957491 is an apocalyptic number.

25597957491 is a deficient number, since it is larger than the sum of its proper divisors (12291899085).

25597957491 is a wasteful number, since it uses less digits than its factorization.

25597957491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96463 (or 96460 counting only the distinct ones).

The product of its digits is 35721000, while the sum is 63.

The spelling of 25597957491 in words is "twenty-five billion, five hundred ninety-seven million, nine hundred fifty-seven thousand, four hundred ninety-one".