666725823 has 20 divisors (see below), whose sum is σ = 997210368. Its totient is φ = 443931840.

The previous prime is 666725821. The next prime is 666725831. The reversal of 666725823 is 328527666.

It is a happy number.

It is not a de Polignac number, because 666725823 - 2¹ = 666725821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666725821) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 66690 + ... + 76032.

Almost surely, 2^666725823 is an apocalyptic number.

666725823 is a deficient number, since it is larger than the sum of its proper divisors (330484545).

666725823 is an equidigital number, since it uses as much as digits as its factorization.

666725823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10236 (or 10227 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 666725823 is about 25821.0345067737. The cubic root of 666725823 is about 873.6063028807.

The spelling of 666725823 in words is "six hundred sixty-six million, seven hundred twenty-five thousand, eight hundred twenty-three".