18073631 has 4 divisors (see below), whose sum is σ = 18493992. Its totient is φ = 17653272.

The previous prime is 18073619. The next prime is 18073637. The reversal of 18073631 is 13637081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13637081 = 251 ⋅54331.

It is a cyclic number.

It is not a de Polignac number, because 18073631 - 2¹⁸ = 17811487 is a prime.

It is a super-2 number, since 2×18073631² = 653312275048322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18073594 and 18073603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18073637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210116 + ... + 210201.

It is an arithmetic number, because the mean of its divisors is an integer number (4623498).

Almost surely, 2^18073631 is an apocalyptic number.

18073631 is a deficient number, since it is larger than the sum of its proper divisors (420361).

18073631 is an equidigital number, since it uses as much as digits as its factorization.

18073631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420360.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 18073631 is about 4251.3093277248. The cubic root of 18073631 is about 262.4310010638.

The spelling of 18073631 in words is "eighteen million, seventy-three thousand, six hundred thirty-one".