25615493957 has 4 divisors (see below), whose sum is σ = 25617133740. Its totient is φ = 25613854176.

The previous prime is 25615493927. The next prime is 25615493977. The reversal of 25615493957 is 75939451652.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18282825796 + 7332668161 = 135214^2 + 85631^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25615493957 is a prime.

It is a super-2 number, since 2×25615493957² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25615493927) 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, 796232 + ... + 827777.

It is an arithmetic number, because the mean of its divisors is an integer number (6404283435).

Almost surely, 2^25615493957 is an apocalyptic number.

It is an amenable number.

25615493957 is a deficient number, since it is larger than the sum of its proper divisors (1639783).

25615493957 is a wasteful number, since it uses less digits than its factorization.

25615493957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1639782.

The product of its digits is 10206000, while the sum is 56.

The spelling of 25615493957 in words is "twenty-five billion, six hundred fifteen million, four hundred ninety-three thousand, nine hundred fifty-seven".