640889580 has 48 divisors (see below), whose sum is σ = 1842996960. Its totient is φ = 166284288.

The previous prime is 640889569. The next prime is 640889581. The reversal of 640889580 is 85988046.

640889580 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (640889581) 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, 142125 + ... + 146564.

It is an arithmetic number, because the mean of its divisors is an integer number (38395770).

Almost surely, 2^640889580 is an apocalyptic number.

640889580 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640889580 is an abundant number, since it is smaller than the sum of its proper divisors (1202107380).

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

640889580 is a wasteful number, since it uses less digits than its factorization.

640889580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288738 (or 288736 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 48.

The square root of 640889580 is about 25315.7970445333. The cubic root of 640889580 is about 862.1729707458.

The spelling of 640889580 in words is "six hundred forty million, eight hundred eighty-nine thousand, five hundred eighty".