18718937 has 4 divisors (see below), whose sum is σ = 18982656. Its totient is φ = 18455220.

The previous prime is 18718927. The next prime is 18718939. The reversal of 18718937 is 73981781.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18718937 - 2⁶ = 18718873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18718939) 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, 131753 + ... + 131894.

It is an arithmetic number, because the mean of its divisors is an integer number (4745664).

Almost surely, 2^18718937 is an apocalyptic number.

It is an amenable number.

18718937 is a deficient number, since it is larger than the sum of its proper divisors (263719).

18718937 is an equidigital number, since it uses as much as digits as its factorization.

18718937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263718.

The product of its digits is 84672, while the sum is 44.

The square root of 18718937 is about 4326.5386858319. The cubic root of 18718937 is about 265.5178529235.

The spelling of 18718937 in words is "eighteen million, seven hundred eighteen thousand, nine hundred thirty-seven".