669623761 has 4 divisors (see below), whose sum is σ = 709013412. Its totient is φ = 630234112.

The previous prime is 669623719. The next prime is 669623789. The reversal of 669623761 is 167326966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 167326966 = 2 ⋅83663483.

It can be written as a sum of positive squares in 2 ways, for example, as 294465600 + 375158161 = 17160^2 + 19369^2 .

It is a cyclic number.

It is not a de Polignac number, because 669623761 - 2¹¹ = 669621713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669623701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19694800 + ... + 19694833.

It is an arithmetic number, because the mean of its divisors is an integer number (177253353).

Almost surely, 2^669623761 is an apocalyptic number.

It is an amenable number.

669623761 is a deficient number, since it is larger than the sum of its proper divisors (39389651).

669623761 is a wasteful number, since it uses less digits than its factorization.

669623761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39389650.

The product of its digits is 489888, while the sum is 46.

The square root of 669623761 is about 25877.0895001737. The cubic root of 669623761 is about 874.8701896137.

The spelling of 669623761 in words is "six hundred sixty-nine million, six hundred twenty-three thousand, seven hundred sixty-one".