6665646 has 32 divisors (see below), whose sum is σ = 14521248. Its totient is φ = 2027520.

The previous prime is 6665639. The next prime is 6665669. The reversal of 6665646 is 6465666.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7126 + ... + 8006.

It is an arithmetic number, because the mean of its divisors is an integer number (453789).

Almost surely, 2^6665646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6665646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7260624).

6665646 is an abundant number, since it is smaller than the sum of its proper divisors (7855602).

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

6665646 is a wasteful number, since it uses less digits than its factorization.

6665646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 996.

The product of its digits is 155520, while the sum is 39.

The square root of 6665646 is about 2581.7912386558. The cubic root of 6665646 is about 188.1976004449.

The spelling of 6665646 in words is "six million, six hundred sixty-five thousand, six hundred forty-six".