25717515623 has 4 divisors (see below), whose sum is σ = 25887830448. Its totient is φ = 25547200800.

The previous prime is 25717515617. The next prime is 25717515631. The reversal of 25717515623 is 32651571752.

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

It is a cyclic number.

It is not a de Polignac number, because 25717515623 - 2¹⁸ = 25717253479 is a prime.

It is a super-2 number, since 2×25717515623² (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 (25717515613) 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, 85157186 + ... + 85157487.

It is an arithmetic number, because the mean of its divisors is an integer number (6471957612).

Almost surely, 2^25717515623 is an apocalyptic number.

25717515623 is a deficient number, since it is larger than the sum of its proper divisors (170314825).

25717515623 is a wasteful number, since it uses less digits than its factorization.

25717515623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170314824.

The product of its digits is 441000, while the sum is 44.

The spelling of 25717515623 in words is "twenty-five billion, seven hundred seventeen million, five hundred fifteen thousand, six hundred twenty-three".