28181975 has 12 divisors (see below), whose sum is σ = 35891304. Its totient is φ = 21935520.

The previous prime is 28181963. The next prime is 28181977. The reversal of 28181975 is 57918182.

It is not a de Polignac number, because 28181975 - 2⁶ = 28181911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28181977) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14309 + ... + 16158.

It is an arithmetic number, because the mean of its divisors is an integer number (2990942).

Almost surely, 2^28181975 is an apocalyptic number.

28181975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28181975 is a deficient number, since it is larger than the sum of its proper divisors (7709329).

28181975 is a wasteful number, since it uses less digits than its factorization.

28181975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30514 (or 30509 counting only the distinct ones).

The product of its digits is 40320, while the sum is 41.

The square root of 28181975 is about 5308.6697957210. The cubic root of 28181975 is about 304.3153144286.

The spelling of 28181975 in words is "twenty-eight million, one hundred eighty-one thousand, nine hundred seventy-five".