18943991946 has 24 divisors (see below), whose sum is σ = 44776708704. Its totient is φ = 5740603560.

The previous prime is 18943991923. The next prime is 18943991951. The reversal of 18943991946 is 64919934981.

18943991946 is a `hidden beast` number, since 1 + 8 + 9 + 439 + 9 + 194 + 6 = 666.

It is a super-2 number, since 2×18943991946² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 47838166 + ... + 47838561.

It is an arithmetic number, because the mean of its divisors is an integer number (1865696196).

Almost surely, 2^18943991946 is an apocalyptic number.

18943991946 is an abundant number, since it is smaller than the sum of its proper divisors (25832716758).

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

18943991946 is a wasteful number, since it uses less digits than its factorization.

18943991946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95676746 (or 95676743 counting only the distinct ones).

The product of its digits is 15116544, while the sum is 63.

The spelling of 18943991946 in words is "eighteen billion, nine hundred forty-three million, nine hundred ninety-one thousand, nine hundred forty-six".