640762322561 has 8 divisors (see below), whose sum is σ = 644896874880. Its totient is φ = 636640752528.

The previous prime is 640762322539. The next prime is 640762322567. The reversal of 640762322561 is 165223267046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640762322561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640762322567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3146531 + ... + 3343976.

It is an arithmetic number, because the mean of its divisors is an integer number (80612109360).

Almost surely, 2^640762322561 is an apocalyptic number.

It is an amenable number.

640762322561 is a deficient number, since it is larger than the sum of its proper divisors (4134552319).

640762322561 is a wasteful number, since it uses less digits than its factorization.

640762322561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6491143.

The product of its (nonzero) digits is 725760, while the sum is 44.

The spelling of 640762322561 in words is "six hundred forty billion, seven hundred sixty-two million, three hundred twenty-two thousand, five hundred sixty-one".