18718971 has 16 divisors (see below), whose sum is σ = 26611200. Its totient is φ = 11670048.

The previous prime is 18718969. The next prime is 18718979. The reversal of 18718971 is 17981781.

It is a happy number.

It is not a de Polignac number, because 18718971 - 2¹ = 18718969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18718979) 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, 2425 + ... + 6581.

It is an arithmetic number, because the mean of its divisors is an integer number (1663200).

Almost surely, 2^18718971 is an apocalyptic number.

18718971 is a deficient number, since it is larger than the sum of its proper divisors (7892229).

18718971 is a wasteful number, since it uses less digits than its factorization.

18718971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4258.

The product of its digits is 28224, while the sum is 42.

The square root of 18718971 is about 4326.5426150681. The cubic root of 18718971 is about 265.5180136805.

The spelling of 18718971 in words is "eighteen million, seven hundred eighteen thousand, nine hundred seventy-one".