18361579504381 has 2 divisors, whose sum is σ = 18361579504382. Its totient is φ = 18361579504380.

The previous prime is 18361579504379. The next prime is 18361579504469. The reversal of 18361579504381 is 18340597516381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15170175901881 + 3191403602500 = 3894891^2 + 1786450^2 .

It is a cyclic number.

It is not a de Polignac number, because 18361579504381 - 2¹ = 18361579504379 is a prime.

It is a super-2 number, since 2×18361579504381² (a number of 27 digits) contains 22 as substring.

Together with 18361579504379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18361579504321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9180789752190 + 9180789752191.

It is an arithmetic number, because the mean of its divisors is an integer number (9180789752191).

Almost surely, 2^{18361579504381} is an apocalyptic number.

It is an amenable number.

18361579504381 is a deficient number, since it is larger than the sum of its proper divisors (1).

18361579504381 is an equidigital number, since it uses as much as digits as its factorization.

18361579504381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21772800, while the sum is 61.

The spelling of 18361579504381 in words is "eighteen trillion, three hundred sixty-one billion, five hundred seventy-nine million, five hundred four thousand, three hundred eighty-one".