663406503032561 has 4 divisors (see below), whose sum is σ = 663431063664624. Its totient is φ = 663381942400500.

The previous prime is 663406503032551. The next prime is 663406503032563. The reversal of 663406503032561 is 165230305604366.

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 a de Polignac number, because none of the positive numbers 2^k-663406503032561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663406503032563) 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, 12280275515 + ... + 12280329536.

It is an arithmetic number, because the mean of its divisors is an integer number (165857765916156).

Almost surely, 2^{663406503032561} is an apocalyptic number.

It is an amenable number.

663406503032561 is a deficient number, since it is larger than the sum of its proper divisors (24560632063).

663406503032561 is a wasteful number, since it uses less digits than its factorization.

663406503032561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24560632062.

The product of its (nonzero) digits is 6998400, while the sum is 50.

The spelling of 663406503032561 in words is "six hundred sixty-three trillion, four hundred six billion, five hundred three million, thirty-two thousand, five hundred sixty-one".