669637720 has 16 divisors (see below), whose sum is σ = 1506684960. Its totient is φ = 267855072.

The previous prime is 669637697. The next prime is 669637721. The reversal of 669637720 is 27736966.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669637721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8370432 + ... + 8370511.

It is an arithmetic number, because the mean of its divisors is an integer number (94167810).

Almost surely, 2^669637720 is an apocalyptic number.

It is an amenable number.

669637720 is an abundant number, since it is smaller than the sum of its proper divisors (837047240).

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

669637720 is a wasteful number, since it uses less digits than its factorization.

669637720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16740954 (or 16740950 counting only the distinct ones).

The product of its (nonzero) digits is 571536, while the sum is 46.

The square root of 669637720 is about 25877.3592161179. The cubic root of 669637720 is about 874.8762687628.

The spelling of 669637720 in words is "six hundred sixty-nine million, six hundred thirty-seven thousand, seven hundred twenty".