669746880 has 504 divisors, whose sum is σ = 2699583120. Its totient is φ = 156764160.

The previous prime is 669746873. The next prime is 669746881. The reversal of 669746880 is 88647966.

669746880 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669746881) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 23094706 + ... + 23094734.

Almost surely, 2^669746880 is an apocalyptic number.

669746880 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 669746880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1349791560).

669746880 is an abundant number, since it is smaller than the sum of its proper divisors (2029836240).

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

669746880 is an equidigital number, since it uses as much as digits as its factorization.

669746880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The square root of 669746880 is about 25879.4683098398. The cubic root of 669746880 is about 874.9238050658.

The spelling of 669746880 in words is "six hundred sixty-nine million, seven hundred forty-six thousand, eight hundred eighty".