6639877 has 4 divisors (see below), whose sum is σ = 7030476. Its totient is φ = 6249280.

The previous prime is 6639863. The next prime is 6639881. The reversal of 6639877 is 7789366.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3996001 + 2643876 = 1999^2 + 1626^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6639877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6639817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195274 + ... + 195307.

It is an arithmetic number, because the mean of its divisors is an integer number (1757619).

Almost surely, 2^6639877 is an apocalyptic number.

It is an amenable number.

6639877 is a deficient number, since it is larger than the sum of its proper divisors (390599).

6639877 is a wasteful number, since it uses less digits than its factorization.

6639877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390598.

The product of its digits is 381024, while the sum is 46.

The square root of 6639877 is about 2576.7958786058. The cubic root of 6639877 is about 187.9547669207.

The spelling of 6639877 in words is "six million, six hundred thirty-nine thousand, eight hundred seventy-seven".