646641772 has 48 divisors (see below), whose sum is σ = 1340416000. Its totient is φ = 267105600.

The previous prime is 646641731. The next prime is 646641833. The reversal of 646641772 is 277146646.

646641772 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 233854 + ... + 236602.

Almost surely, 2^646641772 is an apocalyptic number.

646641772 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646641772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (670208000).

646641772 is an abundant number, since it is smaller than the sum of its proper divisors (693774228).

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

646641772 is a wasteful number, since it uses less digits than its factorization.

646641772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3062 (or 3060 counting only the distinct ones).

The product of its digits is 338688, while the sum is 43.

The square root of 646641772 is about 25429.1520110286. The cubic root of 646641772 is about 864.7447193492.

The spelling of 646641772 in words is "six hundred forty-six million, six hundred forty-one thousand, seven hundred seventy-two".