18889931 has 4 divisors (see below), whose sum is σ = 19199664. Its totient is φ = 18580200.

The previous prime is 18889921. The next prime is 18889957. The reversal of 18889931 is 13998881.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18889931 - 2¹⁸ = 18627787 is a prime.

It is a super-2 number, since 2×18889931² = 713658986369522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18889921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 154775 + ... + 154896.

It is an arithmetic number, because the mean of its divisors is an integer number (4799916).

Almost surely, 2^18889931 is an apocalyptic number.

18889931 is a deficient number, since it is larger than the sum of its proper divisors (309733).

18889931 is an equidigital number, since it uses as much as digits as its factorization.

18889931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309732.

The product of its digits is 124416, while the sum is 47.

The square root of 18889931 is about 4346.2548245587. The cubic root of 18889931 is about 266.3238889169.

The spelling of 18889931 in words is "eighteen million, eight hundred eighty-nine thousand, nine hundred thirty-one".