669056640 has 256 divisors, whose sum is σ = 2476984320. Its totient is φ = 150441984.

The previous prime is 669056621. The next prime is 669056653. The reversal of 669056640 is 46650966.

669056640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 669056592 and 669056601.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 900109 + ... + 900851.

It is an arithmetic number, because the mean of its divisors is an integer number (9675720).

Almost surely, 2^669056640 is an apocalyptic number.

669056640 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 669056640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1238492160).

669056640 is an abundant number, since it is smaller than the sum of its proper divisors (1807927680).

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

669056640 is a wasteful number, since it uses less digits than its factorization.

669056640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839 (or 827 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 42.

The square root of 669056640 is about 25866.1292040382. The cubic root of 669056640 is about 874.6231367556.

The spelling of 669056640 in words is "six hundred sixty-nine million, fifty-six thousand, six hundred forty".