669987 has 24 divisors (see below), whose sum is σ = 1067040. Its totient is φ = 403200.

The previous prime is 669971. The next prime is 669989. The reversal of 669987 is 789966.

669987 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 669987 - 2⁴ = 669971 is a prime.

669987 is strictly pandigital in base 7.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669987.

It is not an unprimeable number, because it can be changed into a prime (669989) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4362 + ... + 4512.

It is an arithmetic number, because the mean of its divisors is an integer number (44460).

2⁶⁶⁹⁹⁸⁷ is an apocalyptic number.

669987 is a deficient number, since it is larger than the sum of its proper divisors (397053).

669987 is a wasteful number, since it uses less digits than its factorization.

669987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203 (or 200 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 669987 is about 818.5273361348. The cubic root of 669987 is about 87.5028352823.

It can be divided in two parts, 6699 and 87, that added together give a triangular number (6786 = T₁₁₆).

The spelling of 669987 in words is "six hundred sixty-nine thousand, nine hundred eighty-seven".