640385082 has 64 divisors (see below), whose sum is σ = 1515024000. Its totient is φ = 199926144.

The previous prime is 640385077. The next prime is 640385099. The reversal of 640385082 is 280583046.

640385082 is a `hidden beast` number, since 640 + 3 + 8 + 5 + 0 + 8 + 2 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 87808 + ... + 94820.

It is an arithmetic number, because the mean of its divisors is an integer number (23672250).

Almost surely, 2^640385082 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640385082, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (757512000).

640385082 is an abundant number, since it is smaller than the sum of its proper divisors (874638918).

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

640385082 is a wasteful number, since it uses less digits than its factorization.

640385082 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7132 (or 7126 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 640385082 is about 25305.8309881339. The cubic root of 640385082 is about 861.9466817795.

The spelling of 640385082 in words is "six hundred forty million, three hundred eighty-five thousand, eighty-two".