640890930 has 16 divisors (see below), whose sum is σ = 1538138304. Its totient is φ = 170904240.

The previous prime is 640890917. The next prime is 640890997. The reversal of 640890930 is 39098046.

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, 10681486 + ... + 10681545.

It is an arithmetic number, because the mean of its divisors is an integer number (96133644).

Almost surely, 2^640890930 is an apocalyptic number.

640890930 is an abundant number, since it is smaller than the sum of its proper divisors (897247374).

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

640890930 is a wasteful number, since it uses less digits than its factorization.

640890930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21363041.

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 640890930 is about 25315.8237077129. The cubic root of 640890930 is about 862.1735761193.

The spelling of 640890930 in words is "six hundred forty million, eight hundred ninety thousand, nine hundred thirty".