642021981904 has 40 divisors (see below), whose sum is σ = 1250812933920. Its totient is φ = 319233065088.

The previous prime is 642021981871. The next prime is 642021982003. The reversal of 642021981904 is 409189120246.

It is a super-3 number, since 3×642021981904³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6897627 + ... + 6990085.

It is an arithmetic number, because the mean of its divisors is an integer number (31270323348).

Almost surely, 2^642021981904 is an apocalyptic number.

It is an amenable number.

642021981904 is a deficient number, since it is larger than the sum of its proper divisors (608790952016).

642021981904 is a wasteful number, since it uses less digits than its factorization.

642021981904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94867 (or 94861 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 46.

The spelling of 642021981904 in words is "six hundred forty-two billion, twenty-one million, nine hundred eighty-one thousand, nine hundred four".