646809632 has 48 divisors (see below), whose sum is σ = 1463821632. Its totient is φ = 275585280.

The previous prime is 646809623. The next prime is 646809671. The reversal of 646809632 is 236908646.

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, 30407 + ... + 47097.

It is an arithmetic number, because the mean of its divisors is an integer number (30496284).

Almost surely, 2^646809632 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 646809632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (731910816).

646809632 is an abundant number, since it is smaller than the sum of its proper divisors (817012000).

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

646809632 is a wasteful number, since it uses less digits than its factorization.

646809632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16881 (or 16873 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 44.

The square root of 646809632 is about 25432.4523394815. The cubic root of 646809632 is about 864.8195384615.

The spelling of 646809632 in words is "six hundred forty-six million, eight hundred nine thousand, six hundred thirty-two".