640050690 has 16 divisors (see below), whose sum is σ = 1536121728. Its totient is φ = 170680176.

The previous prime is 640050683. The next prime is 640050757. The reversal of 640050690 is 96050046.

It is a super-2 number, since 2×640050690² = 819329771538952200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 21335023 = 640050690 / (6 + 4 + 0 + 0 + 5 + 0 + 6 + 9 + 0).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10667482 + ... + 10667541.

It is an arithmetic number, because the mean of its divisors is an integer number (96007608).

Almost surely, 2^640050690 is an apocalyptic number.

640050690 is an abundant number, since it is smaller than the sum of its proper divisors (896071038).

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

640050690 is a wasteful number, since it uses less digits than its factorization.

640050690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21335033.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 640050690 is about 25299.2231106016. The cubic root of 640050690 is about 861.7966271401.

The spelling of 640050690 in words is "six hundred forty million, fifty thousand, six hundred ninety".