18816971 has 6 divisors (see below), whose sum is σ = 19010772. Its totient is φ = 18624060.

The previous prime is 18816923. The next prime is 18816983. The reversal of 18816971 is 17961881.

It is not a de Polignac number, because 18816971 - 2²² = 14622667 is a prime.

It is a super-2 number, since 2×18816971² = 708156795229682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18816901) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 49460 + ... + 49838.

It is an arithmetic number, because the mean of its divisors is an integer number (3168462).

Almost surely, 2^18816971 is an apocalyptic number.

18816971 is a deficient number, since it is larger than the sum of its proper divisors (193801).

18816971 is an frugal number, since it uses more digits than its factorization.

18816971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889 (or 510 counting only the distinct ones).

The product of its digits is 24192, while the sum is 41.

The square root of 18816971 is about 4337.8532709164. The cubic root of 18816971 is about 265.9805655992.

The spelling of 18816971 in words is "eighteen million, eight hundred sixteen thousand, nine hundred seventy-one".