642635623420 has 96 divisors (see below), whose sum is σ = 1572134376960. Its totient is φ = 216094659840.

The previous prime is 642635623403. The next prime is 642635623433. The reversal of 642635623420 is 24326536246.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2854951 + ... + 3071809.

It is an arithmetic number, because the mean of its divisors is an integer number (16376399760).

Almost surely, 2^642635623420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642635623420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (786067188480).

642635623420 is an abundant number, since it is smaller than the sum of its proper divisors (929498753540).

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

642635623420 is a wasteful number, since it uses less digits than its factorization.

642635623420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217283 (or 217281 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 43.

The spelling of 642635623420 in words is "six hundred forty-two billion, six hundred thirty-five million, six hundred twenty-three thousand, four hundred twenty".