28639838 has 16 divisors (see below), whose sum is σ = 43908480. Its totient is φ = 14007000.

The previous prime is 28639829. The next prime is 28639843. The reversal of 28639838 is 83893682.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 28639792 and 28639801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19013 + ... + 20463.

It is an arithmetic number, because the mean of its divisors is an integer number (2744280).

Almost surely, 2^28639838 is an apocalyptic number.

28639838 is a deficient number, since it is larger than the sum of its proper divisors (15268642).

28639838 is a wasteful number, since it uses less digits than its factorization.

28639838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1663.

The product of its digits is 497664, while the sum is 47.

The square root of 28639838 is about 5351.6201285218. The cubic root of 28639838 is about 305.9545050338.

The spelling of 28639838 in words is "twenty-eight million, six hundred thirty-nine thousand, eight hundred thirty-eight".