640424416 has 48 divisors (see below), whose sum is σ = 1305113040. Its totient is φ = 309104640.

The previous prime is 640424399. The next prime is 640424441. The reversal of 640424416 is 614424046.

It is a congruent number.

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, 153040 + ... + 157168.

It is an arithmetic number, because the mean of its divisors is an integer number (27189855).

Almost surely, 2^640424416 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 640424416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (652556520).

640424416 is an abundant number, since it is smaller than the sum of its proper divisors (664688624).

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

640424416 is a wasteful number, since it uses less digits than its factorization.

640424416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4307 (or 4299 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 31.

The square root of 640424416 is about 25306.6081488610. The cubic root of 640424416 is about 861.9643290346.

The spelling of 640424416 in words is "six hundred forty million, four hundred twenty-four thousand, four hundred sixteen".