28181885 has 16 divisors (see below), whose sum is σ = 34400640. Its totient is φ = 22161600.

The previous prime is 28181863. The next prime is 28181891. The reversal of 28181885 is 58818182.

It is a de Polignac number, because none of the positive numbers 2^k-28181885 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122951 + ... + 123179.

It is an arithmetic number, because the mean of its divisors is an integer number (2150040).

Almost surely, 2^28181885 is an apocalyptic number.

It is an amenable number.

28181885 is a deficient number, since it is larger than the sum of its proper divisors (6218755).

28181885 is a wasteful number, since it uses less digits than its factorization.

28181885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548.

The product of its digits is 40960, while the sum is 41.

The square root of 28181885 is about 5308.6613190144. The cubic root of 28181885 is about 304.3149904815.

The spelling of 28181885 in words is "twenty-eight million, one hundred eighty-one thousand, eight hundred eighty-five".