18027631 has 2 divisors, whose sum is σ = 18027632. Its totient is φ = 18027630.

The previous prime is 18027613. The next prime is 18027643. The reversal of 18027631 is 13672081.

Together with previous prime (18027613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18027631 is a prime.

It is a super-2 number, since 2×18027631² = 649990958944322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18027631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18027661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9013815 + 9013816.

It is an arithmetic number, because the mean of its divisors is an integer number (9013816).

Almost surely, 2^18027631 is an apocalyptic number.

18027631 is a deficient number, since it is larger than the sum of its proper divisors (1).

18027631 is an equidigital number, since it uses as much as digits as its factorization.

18027631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 18027631 is about 4245.8957829886. The cubic root of 18027631 is about 262.2081703172.

The spelling of 18027631 in words is "eighteen million, twenty-seven thousand, six hundred thirty-one".