669725751 has 4 divisors (see below), whose sum is σ = 892967672. Its totient is φ = 446483832.

The previous prime is 669725743. The next prime is 669725773. The reversal of 669725751 is 157527966.

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

It is not a de Polignac number, because 669725751 - 2³ = 669725743 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 669725751.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669725711) 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, 111620956 + ... + 111620961.

It is an arithmetic number, because the mean of its divisors is an integer number (223241918).

Almost surely, 2^669725751 is an apocalyptic number.

669725751 is a deficient number, since it is larger than the sum of its proper divisors (223241921).

669725751 is a wasteful number, since it uses less digits than its factorization.

669725751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223241920.

The product of its digits is 793800, while the sum is 48.

The square root of 669725751 is about 25879.0600872597. The cubic root of 669725751 is about 874.9146043464.

The spelling of 669725751 in words is "six hundred sixty-nine million, seven hundred twenty-five thousand, seven hundred fifty-one".