640409753 has 2 divisors, whose sum is σ = 640409754. Its totient is φ = 640409752.

The previous prime is 640409741. The next prime is 640409761. The reversal of 640409753 is 357904046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 613701529 + 26708224 = 24773^2 + 5168^2 .

It is a cyclic number.

It is not a de Polignac number, because 640409753 - 2¹⁸ = 640147609 is a prime.

It is not a weakly prime, because it can be changed into another prime (640409713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320204876 + 320204877.

It is an arithmetic number, because the mean of its divisors is an integer number (320204877).

Almost surely, 2^640409753 is an apocalyptic number.

It is an amenable number.

640409753 is a deficient number, since it is larger than the sum of its proper divisors (1).

640409753 is an equidigital number, since it uses as much as digits as its factorization.

640409753 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 640409753 is about 25306.3184402631. The cubic root of 640409753 is about 861.9577505433.

The spelling of 640409753 in words is "six hundred forty million, four hundred nine thousand, seven hundred fifty-three".