18431961 has 8 divisors (see below), whose sum is σ = 26021664. Its totient is φ = 11565120.

The previous prime is 18431951. The next prime is 18431971. The reversal of 18431961 is 16913481.

It is an interprime number because it is at equal distance from previous prime (18431951) and next prime (18431971).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-18431961 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18431951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180655 + ... + 180756.

It is an arithmetic number, because the mean of its divisors is an integer number (3252708).

Almost surely, 2^18431961 is an apocalyptic number.

It is an amenable number.

18431961 is a deficient number, since it is larger than the sum of its proper divisors (7589703).

18431961 is a wasteful number, since it uses less digits than its factorization.

18431961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361431.

The product of its digits is 5184, while the sum is 33.

The square root of 18431961 is about 4293.2459747841. The cubic root of 18431961 is about 264.1539936048.

The spelling of 18431961 in words is "eighteen million, four hundred thirty-one thousand, nine hundred sixty-one".