18718857 has 20 divisors (see below), whose sum is σ = 29436880. Its totient is φ = 11821464.

The previous prime is 18718807. The next prime is 18718873. The reversal of 18718857 is 75881781.

It is not a de Polignac number, because 18718857 - 2⁶ = 18718793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18718807) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4543 + ... + 7620.

It is an arithmetic number, because the mean of its divisors is an integer number (1471844).

Almost surely, 2^18718857 is an apocalyptic number.

It is an amenable number.

18718857 is a deficient number, since it is larger than the sum of its proper divisors (10718023).

18718857 is a wasteful number, since it uses less digits than its factorization.

18718857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12194 (or 12185 counting only the distinct ones).

The product of its digits is 125440, while the sum is 45.

The square root of 18718857 is about 4326.5294405563. The cubic root of 18718857 is about 265.5174746710.

It can be divided in two parts, 187 and 18857, that added together give a square (19044 = 138²).

The spelling of 18718857 in words is "eighteen million, seven hundred eighteen thousand, eight hundred fifty-seven".