642405289856 has 64 divisors (see below), whose sum is σ = 1396442799360. Its totient is φ = 291938342400.

The previous prime is 642405289849. The next prime is 642405289873. The reversal of 642405289856 is 658982504246.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-5 number, since 5×642405289856⁵ (a number of 60 digits) contains 55555 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 642405289795 and 642405289804.

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, 6692441 + ... + 6787751.

It is an arithmetic number, because the mean of its divisors is an integer number (21819418740).

Almost surely, 2^642405289856 is an apocalyptic number.

It is an amenable number.

642405289856 is an abundant number, since it is smaller than the sum of its proper divisors (754037509504).

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

642405289856 is a wasteful number, since it uses less digits than its factorization.

642405289856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100123 (or 100111 counting only the distinct ones).

The product of its (nonzero) digits is 33177600, while the sum is 59.

The spelling of 642405289856 in words is "six hundred forty-two billion, four hundred five million, two hundred eighty-nine thousand, eight hundred fifty-six".