18536989 has 6 divisors (see below), whose sum is σ = 19564350. Its totient is φ = 17561016.

The previous prime is 18536929. The next prime is 18537019. The reversal of 18536989 is 98963581.

It can be written as a sum of positive squares in only one way, i.e., 11957764 + 6579225 = 3458^2 + 2565^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18536989 is a prime.

It is a super-2 number, since 2×18536989² = 687239922372242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18536929) 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 5 ways as a sum of consecutive naturals, for example, 25314 + ... + 26035.

It is an arithmetic number, because the mean of its divisors is an integer number (3260725).

Almost surely, 2^18536989 is an apocalyptic number.

18536989 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18536989 is a deficient number, since it is larger than the sum of its proper divisors (1027361).

18536989 is an equidigital number, since it uses as much as digits as its factorization.

18536989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51387 (or 51368 counting only the distinct ones).

The product of its digits is 466560, while the sum is 49.

The square root of 18536989 is about 4305.4603702740. The cubic root of 18536989 is about 264.6547729521.

The spelling of 18536989 in words is "eighteen million, five hundred thirty-six thousand, nine hundred eighty-nine".