640456416557 has 4 divisors (see below), whose sum is σ = 640458119520. Its totient is φ = 640454713596.

The previous prime is 640456416529. The next prime is 640456416563. The reversal of 640456416557 is 755614654046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640456416557 - 2¹⁴ = 640456400173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640456416499 and 640456416508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640456416527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10457 + ... + 1131822.

It is an arithmetic number, because the mean of its divisors is an integer number (160114529880).

Almost surely, 2^640456416557 is an apocalyptic number.

It is an amenable number.

640456416557 is a deficient number, since it is larger than the sum of its proper divisors (1702963).

640456416557 is a wasteful number, since it uses less digits than its factorization.

640456416557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1702962.

The product of its (nonzero) digits is 12096000, while the sum is 53.

The spelling of 640456416557 in words is "six hundred forty billion, four hundred fifty-six million, four hundred sixteen thousand, five hundred fifty-seven".