18956977965981 has 24 divisors (see below), whose sum is σ = 30507167643264. Its totient is φ = 11244629093760.

The previous prime is 18956977965979. The next prime is 18956977966007.

18956977965981 is a `hidden beast` number, since 1 + 8 + 9 + 5 + 6 + 9 + 7 + 7 + 9 + 6 + 598 + 1 = 666.

18956977965981 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18956977965981 - 2¹ = 18956977965979 is a prime.

It is a super-2 number, since 2×18956977965981² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18956977965891 and 18956977965900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18956977965281) 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 in 23 ways as a sum of consecutive naturals, for example, 2037065836 + ... + 2037075141.

It is an arithmetic number, because the mean of its divisors is an integer number (1271131985136).

Almost surely, 2^{18956977965981} is an apocalyptic number.

18956977965981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18956977965981 is a deficient number, since it is larger than the sum of its proper divisors (11550189677283).

18956977965981 is a wasteful number, since it uses less digits than its factorization.

18956977965981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4074141041 (or 4074141038 counting only the distinct ones).

The product of its digits is 18517766400, while the sum is 90.

The spelling of 18956977965981 in words is "eighteen trillion, nine hundred fifty-six billion, nine hundred seventy-seven million, nine hundred sixty-five thousand, nine hundred eighty-one".