669843691 has 16 divisors (see below), whose sum is σ = 772724736. Its totient is φ = 574920000.

The previous prime is 669843679. The next prime is 669843719. The reversal of 669843691 is 196348966.

It is a cyclic number.

It is not a de Polignac number, because 669843691 - 2²⁹ = 132972779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669843611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9975 + ... + 37936.

It is an arithmetic number, because the mean of its divisors is an integer number (48295296).

Almost surely, 2^669843691 is an apocalyptic number.

669843691 is a deficient number, since it is larger than the sum of its proper divisors (102881045).

669843691 is a wasteful number, since it uses less digits than its factorization.

669843691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47994.

The product of its digits is 1679616, while the sum is 52.

The square root of 669843691 is about 25881.3386632145. The cubic root of 669843691 is about 874.9659593832.

The spelling of 669843691 in words is "six hundred sixty-nine million, eight hundred forty-three thousand, six hundred ninety-one".