25720814691 has 48 divisors (see below), whose sum is σ = 45944720640. Its totient is φ = 13631924160.

The previous prime is 25720814659. The next prime is 25720814699. The reversal of 25720814691 is 19641802752.

25720814691 is a `hidden beast` number, since 2 + 572 + 0 + 8 + 14 + 69 + 1 = 666.

It is not a de Polignac number, because 25720814691 - 2⁵ = 25720814659 is a prime.

It is a super-2 number, since 2×25720814691² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (25720814699) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 501471 + ... + 550376.

It is an arithmetic number, because the mean of its divisors is an integer number (957181680).

Almost surely, 2^25720814691 is an apocalyptic number.

25720814691 is a deficient number, since it is larger than the sum of its proper divisors (20223905949).

25720814691 is a wasteful number, since it uses less digits than its factorization.

25720814691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1051896 (or 1051893 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 25720814691 in words is "twenty-five billion, seven hundred twenty million, eight hundred fourteen thousand, six hundred ninety-one".