18518531 has 2 divisors, whose sum is σ = 18518532. Its totient is φ = 18518530.

The previous prime is 18518503. The next prime is 18518551. The reversal of 18518531 is 13581581.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18518531 - 2¹⁴ = 18502147 is a prime.

It is a super-2 number, since 2×18518531² = 685871980795922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18518551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9259265 + 9259266.

It is an arithmetic number, because the mean of its divisors is an integer number (9259266).

Almost surely, 2^18518531 is an apocalyptic number.

18518531 is a deficient number, since it is larger than the sum of its proper divisors (1).

18518531 is an equidigital number, since it uses as much as digits as its factorization.

18518531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4800, while the sum is 32.

The square root of 18518531 is about 4303.3162793362. The cubic root of 18518531 is about 264.5669014340.

The spelling of 18518531 in words is "eighteen million, five hundred eighteen thousand, five hundred thirty-one".