646609824 has 384 divisors, whose sum is σ = 2409523200. Its totient is φ = 164229120.

The previous prime is 646609823. The next prime is 646609849. The reversal of 646609824 is 428906646.

It is a self number, because there is not a number n which added to its sum of digits gives 646609824.

It is not an unprimeable number, because it can be changed into a prime (646609823) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1953339 + ... + 1953669.

It is an arithmetic number, because the mean of its divisors is an integer number (6274800).

Almost surely, 2^646609824 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 646609824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1204761600).

646609824 is an abundant number, since it is smaller than the sum of its proper divisors (1762913376).

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

646609824 is a wasteful number, since it uses less digits than its factorization.

646609824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 379 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 646609824 is about 25428.5238266007. The cubic root of 646609824 is about 864.7304779147.

The spelling of 646609824 in words is "six hundred forty-six million, six hundred nine thousand, eight hundred twenty-four".