18946668521 has 16 divisors (see below), whose sum is σ = 21891980160. Its totient is φ = 16205825280.

The previous prime is 18946668491. The next prime is 18946668581. The reversal of 18946668521 is 12586664981.

It is not a de Polignac number, because 18946668521 - 2³⁰ = 17872926697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18946668581) 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, 634100 + ... + 663306.

It is an arithmetic number, because the mean of its divisors is an integer number (1368248760).

Almost surely, 2^18946668521 is an apocalyptic number.

18946668521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18946668521 is a deficient number, since it is larger than the sum of its proper divisors (2945311639).

18946668521 is a wasteful number, since it uses less digits than its factorization.

18946668521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32704.

The product of its digits is 4976640, while the sum is 56.

The spelling of 18946668521 in words is "eighteen billion, nine hundred forty-six million, six hundred sixty-eight thousand, five hundred twenty-one".