6669440 has 64 divisors (see below), whose sum is σ = 16909560. Its totient is φ = 2506752.

The previous prime is 6669413. The next prime is 6669451. The reversal of 6669440 is 449666.

6669440 = 17² + 18² + ... + 271².

It can be written as a sum of positive squares in 4 ways, for example, as 4032064 + 2637376 = 2008^2 + 1624^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 6669440.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10574 + ... + 11186.

Almost surely, 2^6669440 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 6669440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8454780).

6669440 is an abundant number, since it is smaller than the sum of its proper divisors (10240120).

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

6669440 is a wasteful number, since it uses less digits than its factorization.

6669440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 637 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 6669440 is about 2582.5258953203. The cubic root of 6669440 is about 188.2333002240.

The spelling of 6669440 in words is "six million, six hundred sixty-nine thousand, four hundred forty".