64891121994 has 24 divisors (see below), whose sum is σ = 140612938752. Its totient is φ = 21627988200.

The previous prime is 64891121989. The next prime is 64891122017. The reversal of 64891121994 is 49912119846.

It is a self number, because there is not a number n which added to its sum of digits gives 64891121994.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27082 + ... + 361269.

It is an arithmetic number, because the mean of its divisors is an integer number (5858872448).

Almost surely, 2^64891121994 is an apocalyptic number.

64891121994 is an abundant number, since it is smaller than the sum of its proper divisors (75721816758).

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

64891121994 is a wasteful number, since it uses less digits than its factorization.

64891121994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397642 (or 397639 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 54.

The spelling of 64891121994 in words is "sixty-four billion, eight hundred ninety-one million, one hundred twenty-one thousand, nine hundred ninety-four".