640290698 has 16 divisors (see below), whose sum is σ = 1029283200. Its totient is φ = 297948816.

The previous prime is 640290689. The next prime is 640290713. The reversal of 640290698 is 896092046.

It is a Curzon number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 186398 + ... + 189801.

It is an arithmetic number, because the mean of its divisors is an integer number (64330200).

Almost surely, 2^640290698 is an apocalyptic number.

640290698 is a deficient number, since it is larger than the sum of its proper divisors (388992502).

640290698 is a wasteful number, since it uses less digits than its factorization.

640290698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376261.

The product of its (nonzero) digits is 186624, while the sum is 44.

The square root of 640290698 is about 25303.9660527752. The cubic root of 640290698 is about 861.9043333161.

The spelling of 640290698 in words is "six hundred forty million, two hundred ninety thousand, six hundred ninety-eight".