18975857981 has 8 divisors (see below), whose sum is σ = 19590042624. Its totient is φ = 18361802160.

The previous prime is 18975857977. The next prime is 18975858023.

18975857981 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18975857981 - 2² = 18975857977 is a prime.

It is a super-2 number, since 2×18975857981² (a number of 21 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 (18975857951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 333116 + ... + 385898.

It is an arithmetic number, because the mean of its divisors is an integer number (2448755328).

Almost surely, 2^18975857981 is an apocalyptic number.

It is an amenable number.

18975857981 is a deficient number, since it is larger than the sum of its proper divisors (614184643).

18975857981 is a wasteful number, since it uses less digits than its factorization.

18975857981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64411.

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

The spelling of 18975857981 in words is "eighteen billion, nine hundred seventy-five million, eight hundred fifty-seven thousand, nine hundred eighty-one".