28139817 has 16 divisors (see below), whose sum is σ = 40461120. Its totient is φ = 17337600.

The previous prime is 28139807. The next prime is 28139819. The reversal of 28139817 is 71893182.

It is not a de Polignac number, because 28139817 - 2⁷ = 28139689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28139819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3684 + ... + 8357.

It is an arithmetic number, because the mean of its divisors is an integer number (2528820).

Almost surely, 2^28139817 is an apocalyptic number.

It is an amenable number.

28139817 is a deficient number, since it is larger than the sum of its proper divisors (12321303).

28139817 is a wasteful number, since it uses less digits than its factorization.

28139817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12104.

The product of its digits is 24192, while the sum is 39.

The square root of 28139817 is about 5304.6976351155. The cubic root of 28139817 is about 304.1634948398.

The spelling of 28139817 in words is "twenty-eight million, one hundred thirty-nine thousand, eight hundred seventeen".