669720 has 32 divisors (see below), whose sum is σ = 2009520. Its totient is φ = 178560.

The previous prime is 669707. The next prime is 669733. The reversal of 669720 is 27966.

It is an interprime number because it is at equal distance from previous prime (669707) and next prime (669733).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2671 + ... + 2910.

2⁶⁶⁹⁷²⁰ is an apocalyptic number.

669720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

669720 is an abundant number, since it is smaller than the sum of its proper divisors (1339800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

669720 is a wasteful number, since it uses less digits than its factorization.

669720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5595 (or 5591 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 669720 is about 818.3642220919. The cubic root of 669720 is about 87.4912100014.

The spelling of 669720 in words is "six hundred sixty-nine thousand, seven hundred twenty".