18223631 has 2 divisors, whose sum is σ = 18223632. Its totient is φ = 18223630.

The previous prime is 18223627. The next prime is 18223633. The reversal of 18223631 is 13632281.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18223631 - 2² = 18223627 is a prime.

It is a super-2 number, since 2×18223631² = 664201453648322, which contains 22 as substring.

Together with 18223633, it forms a pair of twin primes.

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 18223631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18223633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9111815 + 9111816.

It is an arithmetic number, because the mean of its divisors is an integer number (9111816).

Almost surely, 2^18223631 is an apocalyptic number.

18223631 is a deficient number, since it is larger than the sum of its proper divisors (1).

18223631 is an equidigital number, since it uses as much as digits as its factorization.

18223631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 26.

The square root of 18223631 is about 4268.9144990267. The cubic root of 18223631 is about 263.1550070062.

The spelling of 18223631 in words is "eighteen million, two hundred twenty-three thousand, six hundred thirty-one".