18557744775581 has 32 divisors (see below), whose sum is σ = 20733307292160. Its totient is φ = 16465631846400.

The previous prime is 18557744775517. The next prime is 18557744775613.

18557744775581 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18557744775581 - 2⁶ = 18557744775517 is a prime.

It is a super-2 number, since 2×18557744775581² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18557744775499 and 18557744775508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18557744775181) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 680230661 + ... + 680257941.

It is an arithmetic number, because the mean of its divisors is an integer number (647915852880).

Almost surely, 2^{18557744775581} is an apocalyptic number.

18557744775581 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18557744775581 is a deficient number, since it is larger than the sum of its proper divisors (2175562516579).

18557744775581 is a wasteful number, since it uses less digits than its factorization.

18557744775581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30965.

The product of its digits is 1536640000, while the sum is 74.

The spelling of 18557744775581 in words is "eighteen trillion, five hundred fifty-seven billion, seven hundred forty-four million, seven hundred seventy-five thousand, five hundred eighty-one".