669488640 has 160 divisors (see below), whose sum is σ = 2156647680. Its totient is φ = 177168384.

The previous prime is 669488597. The next prime is 669488641. The reversal of 669488640 is 46884966.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669488641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1374477 + ... + 1374963.

It is an arithmetic number, because the mean of its divisors is an integer number (13479048).

Almost surely, 2^669488640 is an apocalyptic number.

669488640 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 669488640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1078323840).

669488640 is an abundant number, since it is smaller than the sum of its proper divisors (1487159040).

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

669488640 is a wasteful number, since it uses less digits than its factorization.

669488640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692 (or 676 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 51.

The square root of 669488640 is about 25874.4785454702. The cubic root of 669488640 is about 874.8113400059.

The spelling of 669488640 in words is "six hundred sixty-nine million, four hundred eighty-eight thousand, six hundred forty".