669661344 has 144 divisors (see below), whose sum is σ = 2154690720. Its totient is φ = 202901760.

The previous prime is 669661283. The next prime is 669661357. The reversal of 669661344 is 443166966.

It is a tau number, because it is divible by the number of its divisors (144).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 669661344.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81622 + ... + 89450.

It is an arithmetic number, because the mean of its divisors is an integer number (14963130).

Almost surely, 2^669661344 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669661344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1077345360).

669661344 is an abundant number, since it is smaller than the sum of its proper divisors (1485029376).

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

669661344 is a wasteful number, since it uses less digits than its factorization.

669661344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7865 (or 7845 counting only the distinct ones).

The product of its digits is 559872, while the sum is 45.

The square root of 669661344 is about 25877.8156728886. The cubic root of 669661344 is about 874.8865568302.

The spelling of 669661344 in words is "six hundred sixty-nine million, six hundred sixty-one thousand, three hundred forty-four".