18181408257 has 16 divisors (see below), whose sum is σ = 26962639360. Its totient is φ = 12108690000.

The previous prime is 18181408249. The next prime is 18181408261. The reversal of 18181408257 is 75280418181.

18181408257 is a `hidden beast` number, since 18 + 181 + 408 + 2 + 57 = 666.

It is not a de Polignac number, because 18181408257 - 2³ = 18181408249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18181408757) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 312994 + ... + 366507.

It is an arithmetic number, because the mean of its divisors is an integer number (1685164960).

Almost surely, 2^18181408257 is an apocalyptic number.

It is an amenable number.

18181408257 is a deficient number, since it is larger than the sum of its proper divisors (8781231103).

18181408257 is an equidigital number, since it uses as much as digits as its factorization.

18181408257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680501 (or 680495 counting only the distinct ones).

The product of its (nonzero) digits is 143360, while the sum is 45.

The spelling of 18181408257 in words is "eighteen billion, one hundred eighty-one million, four hundred eight thousand, two hundred fifty-seven".