18957875981 has 24 divisors (see below), whose sum is σ = 20993991480. Its totient is φ = 17105876480.

The previous prime is 18957875957. The next prime is 18957876089.

18957875981 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 5604917956 + 13352958025 = 74866^2 + 115555^2 .

It is not a de Polignac number, because 18957875981 - 2¹⁸ = 18957613837 is a prime.

It is a super-2 number, since 2×18957875981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18957875681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14706785 + ... + 14708073.

It is an arithmetic number, because the mean of its divisors is an integer number (874749645).

Almost surely, 2^18957875981 is an apocalyptic number.

18957875981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18957875981 is a deficient number, since it is larger than the sum of its proper divisors (2036115499).

18957875981 is a wasteful number, since it uses less digits than its factorization.

18957875981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2125 (or 2114 counting only the distinct ones).

The product of its digits is 50803200, while the sum is 68.

The spelling of 18957875981 in words is "eighteen billion, nine hundred fifty-seven million, eight hundred seventy-five thousand, nine hundred eighty-one".