669949623 has 30 divisors (see below), whose sum is σ = 1144811976. Its totient is φ = 382476168.

The previous prime is 669949613. The next prime is 669949663. The reversal of 669949623 is 326949966.

669949623 is a `hidden beast` number, since 6 + 6 + 9 + 9 + 4 + 9 + 623 = 666.

It is not a de Polignac number, because 669949623 - 2⁴ = 669949607 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 669949623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669949613) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 615786 + ... + 616872.

Almost surely, 2^669949623 is an apocalyptic number.

669949623 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

669949623 is a deficient number, since it is larger than the sum of its proper divisors (474862353).

669949623 is an frugal number, since it uses more digits than its factorization.

669949623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2193 (or 1097 counting only the distinct ones).

The product of its digits is 3779136, while the sum is 54.

The square root of 669949623 is about 25883.3850761449. The cubic root of 669949623 is about 875.0120805951.

The spelling of 669949623 in words is "six hundred sixty-nine million, nine hundred forty-nine thousand, six hundred twenty-three".