642826723025720 has 128 divisors (see below), whose sum is σ = 1521522590515200. Its totient is φ = 243951360339456.

The previous prime is 642826723025701. The next prime is 642826723025737. The reversal of 642826723025720 is 27520327628246.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 452279141 + ... + 453698219.

It is an arithmetic number, because the mean of its divisors is an integer number (11886895238400).

Almost surely, 2^{642826723025720} 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 642826723025720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (760761295257600).

642826723025720 is an abundant number, since it is smaller than the sum of its proper divisors (878695867489480).

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

642826723025720 is a wasteful number, since it uses less digits than its factorization.

642826723025720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1423117 (or 1423113 counting only the distinct ones).

The product of its (nonzero) digits is 27095040, while the sum is 56.

The spelling of 642826723025720 in words is "six hundred forty-two trillion, eight hundred twenty-six billion, seven hundred twenty-three million, twenty-five thousand, seven hundred twenty".