640234644 has 48 divisors (see below), whose sum is σ = 1728921600. Its totient is φ = 180606816.

The previous prime is 640234633. The next prime is 640234649. The reversal of 640234644 is 446432046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640234649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41604 + ... + 54875.

It is an arithmetic number, because the mean of its divisors is an integer number (36019200).

Almost surely, 2^640234644 is an apocalyptic number.

It is an amenable number.

640234644 is an abundant number, since it is smaller than the sum of its proper divisors (1088686956).

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

640234644 is a wasteful number, since it uses less digits than its factorization.

640234644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96572 (or 96570 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 33.

The square root of 640234644 is about 25302.8584156020. The cubic root of 640234644 is about 861.8791808889.

The spelling of 640234644 in words is "six hundred forty million, two hundred thirty-four thousand, six hundred forty-four".