640763387701 has 2 divisors, whose sum is σ = 640763387702. Its totient is φ = 640763387700.

The previous prime is 640763387681. The next prime is 640763387707. The reversal of 640763387701 is 107783367046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 585079659025 + 55683728676 = 764905^2 + 235974^2 .

It is a cyclic number.

It is not a de Polignac number, because 640763387701 - 2¹⁷ = 640763256629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640763387707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320381693850 + 320381693851.

It is an arithmetic number, because the mean of its divisors is an integer number (320381693851).

Almost surely, 2^640763387701 is an apocalyptic number.

It is an amenable number.

640763387701 is a deficient number, since it is larger than the sum of its proper divisors (1).

640763387701 is an equidigital number, since it uses as much as digits as its factorization.

640763387701 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3556224, while the sum is 52.

The spelling of 640763387701 in words is "six hundred forty billion, seven hundred sixty-three million, three hundred eighty-seven thousand, seven hundred one".