669407057929 has 3 divisors (see below), whose sum is σ = 669407876103. Its totient is φ = 669406239756.

The previous prime is 669407057899. The next prime is 669407057947. The reversal of 669407057929 is 929750704966.

The square root of 669407057929 is 818173.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 73503343225 + 595903714704 = 271115^2 + 771948^2 .

It is not a de Polignac number, because 669407057929 - 2⁵ = 669407057897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669407057959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 409087 + ... + 1227259.

It is an arithmetic number, because the mean of its divisors is an integer number (223135958701).

Almost surely, 2^669407057929 is an apocalyptic number.

669407057929 is the 818173-rd square number.

669407057929 is the 409087-th centered octagonal number.

It is an amenable number.

669407057929 is a deficient number, since it is larger than the sum of its proper divisors (818174).

669407057929 is an frugal number, since it uses more digits than its factorization.

669407057929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636346 (or 818173 counting only the distinct ones).

The product of its (nonzero) digits is 51438240, while the sum is 64.

Multiplying 669407057929 by its sum of digits (64), we get a square (42842051707456 = 6545384²).

The spelling of 669407057929 in words is "six hundred sixty-nine billion, four hundred seven million, fifty-seven thousand, nine hundred twenty-nine".