640368293 has 2 divisors, whose sum is σ = 640368294. Its totient is φ = 640368292.

The previous prime is 640368283. The next prime is 640368307. The reversal of 640368293 is 392863046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 576096004 + 64272289 = 24002^2 + 8017^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640368293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640368293.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640368283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320184146 + 320184147.

It is an arithmetic number, because the mean of its divisors is an integer number (320184147).

Almost surely, 2^640368293 is an apocalyptic number.

It is an amenable number.

640368293 is a deficient number, since it is larger than the sum of its proper divisors (1).

640368293 is an equidigital number, since it uses as much as digits as its factorization.

640368293 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 41.

The square root of 640368293 is about 25305.4992639940. The cubic root of 640368293 is about 861.9391491508.

The spelling of 640368293 in words is "six hundred forty million, three hundred sixty-eight thousand, two hundred ninety-three".