640738476 has 72 divisors (see below), whose sum is σ = 1867485984. Its totient is φ = 181440000.

The previous prime is 640738471. The next prime is 640738513. The reversal of 640738476 is 674837046.

It is not an unprimeable number, because it can be changed into a prime (640738471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17226 + ... + 39726.

Almost surely, 2^640738476 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 640738476, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (933742992).

640738476 is an abundant number, since it is smaller than the sum of its proper divisors (1226747508).

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

640738476 is a wasteful number, since it uses less digits than its factorization.

640738476 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22631 (or 22626 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 45.

The square root of 640738476 is about 25312.8124869600. The cubic root of 640738476 is about 862.1052065898.

The spelling of 640738476 in words is "six hundred forty million, seven hundred thirty-eight thousand, four hundred seventy-six".