669442591 has 8 divisors (see below), whose sum is σ = 689893344. Its totient is φ = 649116000.

The previous prime is 669442537. The next prime is 669442607. The reversal of 669442591 is 195244966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 669442591 - 2¹⁷ = 669311519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669442511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20035 + ... + 41716.

It is an arithmetic number, because the mean of its divisors is an integer number (86236668).

Almost surely, 2^669442591 is an apocalyptic number.

669442591 is a deficient number, since it is larger than the sum of its proper divisors (20450753).

669442591 is a wasteful number, since it uses less digits than its factorization.

669442591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62081.

The product of its digits is 466560, while the sum is 46.

The square root of 669442591 is about 25873.5886764863. The cubic root of 669442591 is about 874.7912823537.

The spelling of 669442591 in words is "six hundred sixty-nine million, four hundred forty-two thousand, five hundred ninety-one".