669932640 has 384 divisors, whose sum is σ = 2574028800. Its totient is φ = 161740800.

The previous prime is 669932633. The next prime is 669932657. The reversal of 669932640 is 46239966.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4436565 + ... + 4436715.

It is an arithmetic number, because the mean of its divisors is an integer number (6703200).

Almost surely, 2^669932640 is an apocalyptic number.

669932640 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 669932640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1287014400).

669932640 is an abundant number, since it is smaller than the sum of its proper divisors (1904096160).

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

669932640 is a wasteful number, since it uses less digits than its factorization.

669932640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267 (or 253 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 45.

The square root of 669932640 is about 25883.0570064666. The cubic root of 669932640 is about 875.0046867776.

The spelling of 669932640 in words is "six hundred sixty-nine million, nine hundred thirty-two thousand, six hundred forty".