18331031 has 2 divisors, whose sum is σ = 18331032. Its totient is φ = 18331030.

The previous prime is 18331009. The next prime is 18331043. The reversal of 18331031 is 13013381.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18331031 - 2¹⁰ = 18330007 is a prime.

It is a super-2 number, since 2×18331031² = 672053395045922, which contains 22 as substring.

It is a Sophie Germain prime.

It is equal to p_1171163 and since 18331031 and 1171163 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 18330994 and 18331012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18331091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9165515 + 9165516.

It is an arithmetic number, because the mean of its divisors is an integer number (9165516).

It is a self-describing number.

Almost surely, 2^18331031 is an apocalyptic number.

18331031 is a deficient number, since it is larger than the sum of its proper divisors (1).

18331031 is an equidigital number, since it uses as much as digits as its factorization.

18331031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 18331031 is about 4281.4753298367. The cubic root of 18331031 is about 263.6709580986.

The spelling of 18331031 in words is "eighteen million, three hundred thirty-one thousand, thirty-one".