640567400 has 48 divisors (see below), whose sum is σ = 1624717440. Its totient is φ = 232932800.

The previous prime is 640567393. The next prime is 640567409. The reversal of 640567400 is 4765046.

It is not an unprimeable number, because it can be changed into a prime (640567409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 143384 + ... + 147783.

It is an arithmetic number, because the mean of its divisors is an integer number (33848280).

Almost surely, 2^640567400 is an apocalyptic number.

It is an amenable number.

640567400 is an abundant number, since it is smaller than the sum of its proper divisors (984150040).

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

640567400 is a wasteful number, since it uses less digits than its factorization.

640567400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291194 (or 291185 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 640567400 is about 25309.4330240723. The cubic root of 640567400 is about 862.0284729229.

The spelling of 640567400 in words is "six hundred forty million, five hundred sixty-seven thousand, four hundred".