646979634 has 96 divisors (see below), whose sum is σ = 1673443200. Its totient is φ = 180478368.

The previous prime is 646979617. The next prime is 646979689. The reversal of 646979634 is 436979646.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 264264 + ... + 266700.

It is an arithmetic number, because the mean of its divisors is an integer number (17431700).

Almost surely, 2^646979634 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646979634, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (836721600).

646979634 is an abundant number, since it is smaller than the sum of its proper divisors (1026463566).

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

646979634 is a wasteful number, since it uses less digits than its factorization.

646979634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2509 (or 2492 counting only the distinct ones).

The product of its digits is 5878656, while the sum is 54.

The square root of 646979634 is about 25435.7943457640. The cubic root of 646979634 is about 864.8952991208.

The spelling of 646979634 in words is "six hundred forty-six million, nine hundred seventy-nine thousand, six hundred thirty-four".