25665959531 has 4 divisors (see below), whose sum is σ = 25669063464. Its totient is φ = 25662855600.

The previous prime is 25665959513. The next prime is 25665959597. The reversal of 25665959531 is 13595956652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25665959531 is a prime.

It is a super-2 number, since 2×25665959531² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25665956531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1539530 + ... + 1556111.

It is an arithmetic number, because the mean of its divisors is an integer number (6417265866).

Almost surely, 2^25665959531 is an apocalyptic number.

25665959531 is a deficient number, since it is larger than the sum of its proper divisors (3103933).

25665959531 is an equidigital number, since it uses as much as digits as its factorization.

25665959531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3103932.

The product of its digits is 10935000, while the sum is 56.

The spelling of 25665959531 in words is "twenty-five billion, six hundred sixty-five million, nine hundred fifty-nine thousand, five hundred thirty-one".