6638878 has 4 divisors (see below), whose sum is σ = 9958320. Its totient is φ = 3319438.

The previous prime is 6638851. The next prime is 6638893. The reversal of 6638878 is 8788366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8788366 = 2 ⋅4394183.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1659718 + ... + 1659721.

It is an arithmetic number, because the mean of its divisors is an integer number (2489580).

Almost surely, 2^6638878 is an apocalyptic number.

6638878 is a deficient number, since it is larger than the sum of its proper divisors (3319442).

6638878 is a wasteful number, since it uses less digits than its factorization.

6638878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3319441.

The product of its digits is 387072, while the sum is 46.

The square root of 6638878 is about 2576.6020259248. The cubic root of 6638878 is about 187.9453402285.

It can be divided in two parts, 66388 and 78, that added together give a palindrome (66466).

The spelling of 6638878 in words is "six million, six hundred thirty-eight thousand, eight hundred seventy-eight".