18431969 has 4 divisors (see below), whose sum is σ = 18779796. Its totient is φ = 18084144.

The previous prime is 18431951. The next prime is 18431971. The reversal of 18431969 is 96913481.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14531344 + 3900625 = 3812^2 + 1975^2 .

It is a cyclic number.

It is not a de Polignac number, because 18431969 - 2²⁰ = 17383393 is a prime.

It is a super-2 number, since 2×18431969² = 679474962433922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18431999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173834 + ... + 173939.

It is an arithmetic number, because the mean of its divisors is an integer number (4694949).

Almost surely, 2^18431969 is an apocalyptic number.

It is an amenable number.

18431969 is a deficient number, since it is larger than the sum of its proper divisors (347827).

18431969 is an equidigital number, since it uses as much as digits as its factorization.

18431969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347826.

The product of its digits is 46656, while the sum is 41.

The square root of 18431969 is about 4293.2469064800. The cubic root of 18431969 is about 264.1540318216.

The spelling of 18431969 in words is "eighteen million, four hundred thirty-one thousand, nine hundred sixty-nine".