640436628622 has 24 divisors (see below), whose sum is σ = 1138581416376. Its totient is φ = 269294105808.

The previous prime is 640436628599. The next prime is 640436628631. The reversal of 640436628622 is 226826634046.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61646388 + ... + 61656775.

It is an arithmetic number, because the mean of its divisors is an integer number (47440892349).

Almost surely, 2^640436628622 is an apocalyptic number.

640436628622 is a deficient number, since it is larger than the sum of its proper divisors (498144787754).

640436628622 is a wasteful number, since it uses less digits than its factorization.

640436628622 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123303232 (or 123303225 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 49.

The spelling of 640436628622 in words is "six hundred forty billion, four hundred thirty-six million, six hundred twenty-eight thousand, six hundred twenty-two".