640411721807 has 16 divisors (see below), whose sum is σ = 752505761952. Its totient is φ = 537312760320.

The previous prime is 640411721779. The next prime is 640411721819. The reversal of 640411721807 is 708127114046.

It is a cyclic number.

It is not a de Polignac number, because 640411721807 - 2¹⁸ = 640411459663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640411721827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 413123 + ... + 1204779.

It is an arithmetic number, because the mean of its divisors is an integer number (47031610122).

Almost surely, 2^640411721807 is an apocalyptic number.

640411721807 is a deficient number, since it is larger than the sum of its proper divisors (112094040145).

640411721807 is a wasteful number, since it uses less digits than its factorization.

640411721807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797338.

The product of its (nonzero) digits is 75264, while the sum is 41.

The spelling of 640411721807 in words is "six hundred forty billion, four hundred eleven million, seven hundred twenty-one thousand, eight hundred seven".