18996681 has 16 divisors (see below), whose sum is σ = 28087488. Its totient is φ = 11323200.

The previous prime is 18996671. The next prime is 18996683. The reversal of 18996681 is 18669981.

It is not a de Polignac number, because 18996681 - 2⁷ = 18996553 is a prime.

It is a super-2 number, since 2×18996681² = 721747778031522, which contains 22 as substring.

18996681 is a strobogrammatic number because it is the same when read upside-down.

It is a self number, because there is not a number n which added to its sum of digits gives 18996681.

It is not an unprimeable number, because it can be changed into a prime (18996683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2706 + ... + 6731.

It is an arithmetic number, because the mean of its divisors is an integer number (1755468).

Almost surely, 2^18996681 is an apocalyptic number.

18996681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18996681 is a deficient number, since it is larger than the sum of its proper divisors (9090807).

18996681 is a wasteful number, since it uses less digits than its factorization.

18996681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9512.

The product of its digits is 186624, while the sum is 48.

The square root of 18996681 is about 4358.5182115026. The cubic root of 18996681 is about 266.8246263795.

It can be divided in two parts, 18 and 996681, that added together give a palindrome (996699).

The spelling of 18996681 in words is "eighteen million, nine hundred ninety-six thousand, six hundred eighty-one".