25518521107 has 4 divisors (see below), whose sum is σ = 25681059616. Its totient is φ = 25355982600.

The previous prime is 25518521081. The next prime is 25518521117. The reversal of 25518521107 is 70112581552.

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 25518521107 - 2²⁷ = 25384303379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25518521117) 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, 81269019 + ... + 81269332.

It is an arithmetic number, because the mean of its divisors is an integer number (6420264904).

Almost surely, 2^25518521107 is an apocalyptic number.

25518521107 is a deficient number, since it is larger than the sum of its proper divisors (162538509).

25518521107 is a wasteful number, since it uses less digits than its factorization.

25518521107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162538508.

The product of its (nonzero) digits is 28000, while the sum is 37.

The spelling of 25518521107 in words is "twenty-five billion, five hundred eighteen million, five hundred twenty-one thousand, one hundred seven".