6639457 has 8 divisors (see below), whose sum is σ = 7312032. Its totient is φ = 5978400.

The previous prime is 6639449. The next prime is 6639467. The reversal of 6639457 is 7549366.

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

It is a cyclic number.

It is not a de Polignac number, because 6639457 - 2³ = 6639449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6639407) 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, 1644 + ... + 3997.

It is an arithmetic number, because the mean of its divisors is an integer number (914004).

Almost surely, 2^6639457 is an apocalyptic number.

It is an amenable number.

6639457 is a deficient number, since it is larger than the sum of its proper divisors (672575).

6639457 is a wasteful number, since it uses less digits than its factorization.

6639457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5759.

The product of its digits is 136080, while the sum is 40.

The square root of 6639457 is about 2576.7143807570. The cubic root of 6639457 is about 187.9508038620.

Subtracting 6639457 from its reverse (7549366), we obtain a palindrome (909909).

The spelling of 6639457 in words is "six million, six hundred thirty-nine thousand, four hundred fifty-seven".