642815706 has 16 divisors (see below), whose sum is σ = 1384526304. Its totient is φ = 197789424.

The previous prime is 642815699. The next prime is 642815717. The reversal of 642815706 is 607518246.

It is a Harshad number since it is a multiple of its sum of digits (39).

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, 4120536 + ... + 4120691.

It is an arithmetic number, because the mean of its divisors is an integer number (86532894).

Almost surely, 2^642815706 is an apocalyptic number.

642815706 is an abundant number, since it is smaller than the sum of its proper divisors (741710598).

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

642815706 is a wasteful number, since it uses less digits than its factorization.

642815706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8241245.

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 642815706 is about 25353.8104828446. The cubic root of 642815706 is about 863.0358302043.

The spelling of 642815706 in words is "six hundred forty-two million, eight hundred fifteen thousand, seven hundred six".