646704870 has 64 divisors (see below), whose sum is σ = 1821782016. Its totient is φ = 143821440.

The previous prime is 646704853. The next prime is 646704889. The reversal of 646704870 is 78407646.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 33846 + ... + 49385.

It is an arithmetic number, because the mean of its divisors is an integer number (28465344).

Almost surely, 2^646704870 is an apocalyptic number.

646704870 is an abundant number, since it is smaller than the sum of its proper divisors (1175077146).

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

646704870 is a wasteful number, since it uses less digits than its factorization.

646704870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83285.

The product of its (nonzero) digits is 225792, while the sum is 42.

The square root of 646704870 is about 25430.3926434493. The cubic root of 646704870 is about 864.7728451163.

The spelling of 646704870 in words is "six hundred forty-six million, seven hundred four thousand, eight hundred seventy".