18631373066581 has 16 divisors (see below), whose sum is σ = 21209038766208. Its totient is φ = 16201038884800.

The previous prime is 18631373066539. The next prime is 18631373066609. The reversal of 18631373066581 is 18566037313681.

It is not a de Polignac number, because 18631373066581 - 2¹¹ = 18631373064533 is a prime.

It is a super-2 number, since 2×18631373066581² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18631373060581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31979175 + ... + 32556571.

It is an arithmetic number, because the mean of its divisors is an integer number (1325564922888).

Almost surely, 2^{18631373066581} is an apocalyptic number.

18631373066581 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18631373066581 is a deficient number, since it is larger than the sum of its proper divisors (2577665699627).

18631373066581 is a wasteful number, since it uses less digits than its factorization.

18631373066581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704972.

The product of its (nonzero) digits is 13063680, while the sum is 58.

The spelling of 18631373066581 in words is "eighteen trillion, six hundred thirty-one billion, three hundred seventy-three million, sixty-six thousand, five hundred eighty-one".