668723623 has 4 divisors (see below), whose sum is σ = 671086888. Its totient is φ = 666360360.

The previous prime is 668723621. The next prime is 668723633. The reversal of 668723623 is 326327866.

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

It is a cyclic number.

It is not a de Polignac number, because 668723623 - 2¹ = 668723621 is a prime.

It is a super-2 number, since 2×668723623² = 894382567916492258, which contains 22 as substring.

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 668723623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668723621) 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, 1181208 + ... + 1181773.

It is an arithmetic number, because the mean of its divisors is an integer number (167771722).

Almost surely, 2^668723623 is an apocalyptic number.

668723623 is a deficient number, since it is larger than the sum of its proper divisors (2363265).

668723623 is a wasteful number, since it uses less digits than its factorization.

668723623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2363264.

The product of its digits is 435456, while the sum is 43.

The square root of 668723623 is about 25859.6910847752. The cubic root of 668723623 is about 874.4780007069.

The spelling of 668723623 in words is "six hundred sixty-eight million, seven hundred twenty-three thousand, six hundred twenty-three".