6639969 has 8 divisors (see below), whose sum is σ = 10118080. Its totient is φ = 3794256.

The previous prime is 6639943. The next prime is 6639989. The reversal of 6639969 is 9699366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6639969 - 2⁵ = 6639937 is a prime.

It is a super-2 number, since 2×6639969² = 88178376641922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6639929) 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, 158074 + ... + 158115.

It is an arithmetic number, because the mean of its divisors is an integer number (1264760).

Almost surely, 2^6639969 is an apocalyptic number.

It is an amenable number.

6639969 is a deficient number, since it is larger than the sum of its proper divisors (3478111).

6639969 is a wasteful number, since it uses less digits than its factorization.

6639969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316199.

The product of its digits is 472392, while the sum is 48.

The square root of 6639969 is about 2576.8137301714. The cubic root of 6639969 is about 187.9556349969.

The spelling of 6639969 in words is "six million, six hundred thirty-nine thousand, nine hundred sixty-nine".