18161056637 has 2 divisors, whose sum is σ = 18161056638. Its totient is φ = 18161056636.

The previous prime is 18161056619. The next prime is 18161056663. The reversal of 18161056637 is 73665016181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14973437956 + 3187618681 = 122366^2 + 56459^2 .

It is a cyclic number.

It is not a de Polignac number, because 18161056637 - 2¹⁴ = 18161040253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18161056687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9080528318 + 9080528319.

It is an arithmetic number, because the mean of its divisors is an integer number (9080528319).

Almost surely, 2^18161056637 is an apocalyptic number.

It is an amenable number.

18161056637 is a deficient number, since it is larger than the sum of its proper divisors (1).

18161056637 is an equidigital number, since it uses as much as digits as its factorization.

18161056637 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 44.

The spelling of 18161056637 in words is "eighteen billion, one hundred sixty-one million, fifty-six thousand, six hundred thirty-seven".