18916581425 has 24 divisors (see below), whose sum is σ = 26821574976. Its totient is φ = 12964559040.

The previous prime is 18916581367. The next prime is 18916581427. The reversal of 18916581425 is 52418561981.

It is not a de Polignac number, because 18916581425 - 2²⁸ = 18648145969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18916581427) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 317882 + ... + 372668.

It is an arithmetic number, because the mean of its divisors is an integer number (1117565624).

Almost surely, 2^18916581425 is an apocalyptic number.

It is an amenable number.

18916581425 is a deficient number, since it is larger than the sum of its proper divisors (7904993551).

18916581425 is a wasteful number, since it uses less digits than its factorization.

18916581425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56777 (or 56772 counting only the distinct ones).

The product of its digits is 691200, while the sum is 50.

The spelling of 18916581425 in words is "eighteen billion, nine hundred sixteen million, five hundred eighty-one thousand, four hundred twenty-five".