640815319801 has 2 divisors, whose sum is σ = 640815319802. Its totient is φ = 640815319800.

The previous prime is 640815319769. The next prime is 640815319811. The reversal of 640815319801 is 108913518046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 392313069801 + 248502250000 = 626349^2 + 498500^2 .

It is a cyclic number.

It is not a de Polignac number, because 640815319801 - 2⁵ = 640815319769 is a prime.

It is not a weakly prime, because it can be changed into another prime (640815319811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320407659900 + 320407659901.

It is an arithmetic number, because the mean of its divisors is an integer number (320407659901).

Almost surely, 2^640815319801 is an apocalyptic number.

It is an amenable number.

640815319801 is a deficient number, since it is larger than the sum of its proper divisors (1).

640815319801 is an equidigital number, since it uses as much as digits as its factorization.

640815319801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 207360, while the sum is 46.

The spelling of 640815319801 in words is "six hundred forty billion, eight hundred fifteen million, three hundred nineteen thousand, eight hundred one".