6639376 has 40 divisors (see below), whose sum is σ = 13671000. Its totient is φ = 3118080.

The previous prime is 6639349. The next prime is 6639377. The reversal of 6639376 is 6739366.

It can be written as a sum of positive squares in 4 ways, for example, as 389376 + 6250000 = 624^2 + 2500^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a d-powerful number, because it can be written as 6 + 6 + 3¹⁰ + 9² + 3¹⁴ + 7⁶ + 6⁸ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6639377) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18850 + ... + 19198.

It is an arithmetic number, because the mean of its divisors is an integer number (341775).

Almost surely, 2^6639376 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 6639376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6835500).

6639376 is an abundant number, since it is smaller than the sum of its proper divisors (7031624).

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

6639376 is a wasteful number, since it uses less digits than its factorization.

6639376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427 (or 421 counting only the distinct ones).

The product of its digits is 122472, while the sum is 40.

The square root of 6639376 is about 2576.6986630182. The cubic root of 6639376 is about 187.9500395386.

The spelling of 6639376 in words is "six million, six hundred thirty-nine thousand, three hundred seventy-six".