669690720 has 384 divisors, whose sum is σ = 2540160000. Its totient is φ = 164229120.

The previous prime is 669690719. The next prime is 669690727. The reversal of 669690720 is 27096966.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669690727) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3365181 + ... + 3365379.

It is an arithmetic number, because the mean of its divisors is an integer number (6615000).

Almost surely, 2^669690720 is an apocalyptic number.

669690720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669690720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1270080000).

669690720 is an abundant number, since it is smaller than the sum of its proper divisors (1870469280).

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

669690720 is a wasteful number, since it uses less digits than its factorization.

669690720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 269 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 669690720 is about 25878.3832570738. The cubic root of 669690720 is about 874.8993495111.

The spelling of 669690720 in words is "six hundred sixty-nine million, six hundred ninety thousand, seven hundred twenty".