18238630437 has 20 divisors (see below), whose sum is σ = 27272170156. Its totient is φ = 12147122880.

The previous prime is 18238630433. The next prime is 18238630441. The reversal of 18238630437 is 73403683281.

18238630437 is a `hidden beast` number, since 1 + 8 + 2 + 3 + 8 + 630 + 4 + 3 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (18238630433) and next prime (18238630441).

It can be written as a sum of positive squares in 2 ways, for example, as 15439056516 + 2799573921 = 124254^2 + 52911^2 .

It is not a de Polignac number, because 18238630437 - 2² = 18238630433 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18238630392 and 18238630401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18238630433) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 27568 + ... + 192969.

Almost surely, 2^18238630437 is an apocalyptic number.

It is an amenable number.

18238630437 is a deficient number, since it is larger than the sum of its proper divisors (9033539719).

18238630437 is a wasteful number, since it uses less digits than its factorization.

18238630437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221570 (or 221561 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The spelling of 18238630437 in words is "eighteen billion, two hundred thirty-eight million, six hundred thirty thousand, four hundred thirty-seven".