640653517423 has 2 divisors, whose sum is σ = 640653517424. Its totient is φ = 640653517422.

The previous prime is 640653517409. The next prime is 640653517523. The reversal of 640653517423 is 324715356046.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640653517423 - 2³³ = 632063582831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640653517223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320326758711 + 320326758712.

It is an arithmetic number, because the mean of its divisors is an integer number (320326758712).

Almost surely, 2^640653517423 is an apocalyptic number.

640653517423 is a deficient number, since it is larger than the sum of its proper divisors (1).

640653517423 is an equidigital number, since it uses as much as digits as its factorization.

640653517423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1814400, while the sum is 46.

The spelling of 640653517423 in words is "six hundred forty billion, six hundred fifty-three million, five hundred seventeen thousand, four hundred twenty-three".