18313531 has 2 divisors, whose sum is σ = 18313532. Its totient is φ = 18313530.

The previous prime is 18313523. The next prime is 18313553. The reversal of 18313531 is 13531381.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18313531 - 2³ = 18313523 is a prime.

It is a super-2 number, since 2×18313531² = 670770835375922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18313496 and 18313505.

It is not a weakly prime, because it can be changed into another prime (18313501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9156765 + 9156766.

It is an arithmetic number, because the mean of its divisors is an integer number (9156766).

Almost surely, 2^18313531 is an apocalyptic number.

18313531 is a deficient number, since it is larger than the sum of its proper divisors (1).

18313531 is an equidigital number, since it uses as much as digits as its factorization.

18313531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 25.

The square root of 18313531 is about 4279.4311537867. The cubic root of 18313531 is about 263.5870255418.

The spelling of 18313531 in words is "eighteen million, three hundred thirteen thousand, five hundred thirty-one".