640620622444 has 24 divisors (see below), whose sum is σ = 1223154249408. Its totient is φ = 291155181840.

The previous prime is 640620622427. The next prime is 640620622469. The reversal of 640620622444 is 444226026046.

It is a junction number, because it is equal to n+sod(n) for n = 640620622397 and 640620622406.

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 7 ways as a sum of consecutive naturals, for example, 538782 + ... + 1253605.

It is an arithmetic number, because the mean of its divisors is an integer number (50964760392).

Almost surely, 2^640620622444 is an apocalyptic number.

It is an amenable number.

640620622444 is a deficient number, since it is larger than the sum of its proper divisors (582533626964).

640620622444 is a wasteful number, since it uses less digits than its factorization.

640620622444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800525 (or 1800523 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 40.

The spelling of 640620622444 in words is "six hundred forty billion, six hundred twenty million, six hundred twenty-two thousand, four hundred forty-four".