663916723 has 4 divisors (see below), whose sum is σ = 664240608. Its totient is φ = 663592840.

The previous prime is 663916717. The next prime is 663916763. The reversal of 663916723 is 327619366.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-663916723 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 663916723.

It is not an unprimeable number, because it can be changed into a prime (663916763) 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, 158848 + ... + 162973.

It is an arithmetic number, because the mean of its divisors is an integer number (166060152).

Almost surely, 2^663916723 is an apocalyptic number.

663916723 is a deficient number, since it is larger than the sum of its proper divisors (323885).

663916723 is a wasteful number, since it uses less digits than its factorization.

663916723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323884.

The product of its digits is 244944, while the sum is 43.

The square root of 663916723 is about 25766.5815155988. The cubic root of 663916723 is about 872.3776608626.

The spelling of 663916723 in words is "six hundred sixty-three million, nine hundred sixteen thousand, seven hundred twenty-three".