18016631 has 2 divisors, whose sum is σ = 18016632. Its totient is φ = 18016630.

The previous prime is 18016591. The next prime is 18016637. The reversal of 18016631 is 13661081.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18016631 - 2¹⁰ = 18015607 is a prime.

It is a super-2 number, since 2×18016631² = 649197985180322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18016631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18016637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9008315 + 9008316.

It is an arithmetic number, because the mean of its divisors is an integer number (9008316).

Almost surely, 2^18016631 is an apocalyptic number.

18016631 is a deficient number, since it is larger than the sum of its proper divisors (1).

18016631 is an equidigital number, since it uses as much as digits as its factorization.

18016631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 18016631 is about 4244.6002167460. The cubic root of 18016631 is about 262.1548285569.

The spelling of 18016631 in words is "eighteen million, sixteen thousand, six hundred thirty-one".