640674450 has 72 divisors (see below), whose sum is σ = 1853701668. Its totient is φ = 157703040.

The previous prime is 640674449. The next prime is 640674457. The reversal of 640674450 is 54476046.

640674450 is a `hidden beast` number, since 640 + 6 + 7 + 4 + 4 + 5 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 18122049 + 622552401 = 4257^2 + 24951^2 .

It is not an unprimeable number, because it can be changed into a prime (640674457) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 48909 + ... + 60608.

Almost surely, 2^640674450 is an apocalyptic number.

640674450 is an abundant number, since it is smaller than the sum of its proper divisors (1213027218).

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

640674450 is a wasteful number, since it uses less digits than its factorization.

640674450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109548 (or 109540 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The square root of 640674450 is about 25311.5477598664. The cubic root of 640674450 is about 862.0764902525.

The spelling of 640674450 in words is "six hundred forty million, six hundred seventy-four thousand, four hundred fifty".