640829590 has 16 divisors (see below), whose sum is σ = 1181628000. Its totient is φ = 250079680.

The previous prime is 640829557. The next prime is 640829597. The reversal of 640829590 is 95928046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640829597) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 781090 + ... + 781909.

It is an arithmetic number, because the mean of its divisors is an integer number (73851750).

Almost surely, 2^640829590 is an apocalyptic number.

640829590 is a deficient number, since it is larger than the sum of its proper divisors (540798410).

640829590 is a wasteful number, since it uses less digits than its factorization.

640829590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1563047.

The product of its (nonzero) digits is 155520, while the sum is 43.

The square root of 640829590 is about 25314.6121834801. The cubic root of 640829590 is about 862.1460688832.

The spelling of 640829590 in words is "six hundred forty million, eight hundred twenty-nine thousand, five hundred ninety".