28137231 has 24 divisors (see below), whose sum is σ = 41533440. Its totient is φ = 18352656.

The previous prime is 28137209. The next prime is 28137247. The reversal of 28137231 is 13273182.

It is not a de Polignac number, because 28137231 - 2⁵ = 28137199 is a prime.

It is a super-2 number, since 2×28137231² = 1583407536694722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28137195 and 28137204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28137281) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 117610 + ... + 117848.

It is an arithmetic number, because the mean of its divisors is an integer number (1730560).

Almost surely, 2^28137231 is an apocalyptic number.

28137231 is a deficient number, since it is larger than the sum of its proper divisors (13396209).

28137231 is a wasteful number, since it uses less digits than its factorization.

28137231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475 (or 472 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 28137231 is about 5304.4538832947. The cubic root of 28137231 is about 304.1541771899.

The spelling of 28137231 in words is "twenty-eight million, one hundred thirty-seven thousand, two hundred thirty-one".