28117836 has 18 divisors (see below), whose sum is σ = 71075732. Its totient is φ = 9372600.

The previous prime is 28117819. The next prime is 28117871. The reversal of 28117836 is 63871182.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×28117836² = 1581225402645792, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 781051 = 28117836 / (2 + 8 + 1 + 1 + 7 + 8 + 3 + 6).

It is a self number, because there is not a number n which added to its sum of digits gives 28117836.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 390490 + ... + 390561.

Almost surely, 2^28117836 is an apocalyptic number.

It is an amenable number.

28117836 is an abundant number, since it is smaller than the sum of its proper divisors (42957896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28117836 is a wasteful number, since it uses less digits than its factorization.

28117836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 781061 (or 781056 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 28117836 is about 5302.6253874850. The cubic root of 28117836 is about 304.0842766111.

The spelling of 28117836 in words is "twenty-eight million, one hundred seventeen thousand, eight hundred thirty-six".