642447101998 has 24 divisors (see below), whose sum is σ = 1043629785000. Its totient is φ = 296477554464.

The previous prime is 642447101969. The next prime is 642447102001. The reversal of 642447101998 is 899101744246.

It is a happy number.

It is a congruent number.

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, 2736253 + ... + 2961751.

It is an arithmetic number, because the mean of its divisors is an integer number (43484574375).

Almost surely, 2^642447101998 is an apocalyptic number.

642447101998 is a deficient number, since it is larger than the sum of its proper divisors (401182683002).

642447101998 is a wasteful number, since it uses less digits than its factorization.

642447101998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233956 (or 233943 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 55.

The spelling of 642447101998 in words is "six hundred forty-two billion, four hundred forty-seven million, one hundred one thousand, nine hundred ninety-eight".