646990708 has 72 divisors (see below), whose sum is σ = 1464336384. Its totient is φ = 247665600.

The previous prime is 646990699. The next prime is 646990733. The reversal of 646990708 is 807099646.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74893 + ... + 83083.

Almost surely, 2^646990708 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 646990708, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (732168192).

646990708 is an abundant number, since it is smaller than the sum of its proper divisors (817345676).

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

646990708 is a wasteful number, since it uses less digits than its factorization.

646990708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8253 (or 8244 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 49.

The square root of 646990708 is about 25436.0120301906. The cubic root of 646990708 is about 864.9002337408.

The spelling of 646990708 in words is "six hundred forty-six million, nine hundred ninety thousand, seven hundred eight".