18966921564 has 24 divisors (see below), whose sum is σ = 44278018960. Its totient is φ = 6319183104.

The previous prime is 18966921521. The next prime is 18966921569. The reversal of 18966921564 is 46512966981.

It is a super-2 number, since 2×18966921564² (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 (18966921569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365149 + ... + 413844.

Almost surely, 2^18966921564 is an apocalyptic number.

It is an amenable number.

18966921564 is an abundant number, since it is smaller than the sum of its proper divisors (25311097396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18966921564 is a wasteful number, since it uses less digits than its factorization.

18966921564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781029 (or 781027 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 57.

The spelling of 18966921564 in words is "eighteen billion, nine hundred sixty-six million, nine hundred twenty-one thousand, five hundred sixty-four".