28158237 has 6 divisors (see below), whose sum is σ = 40673022. Its totient is φ = 18772152.

The previous prime is 28158191. The next prime is 28158257. The reversal of 28158237 is 73285182.

It can be written as a sum of positive squares in only one way, i.e., 26101881 + 2056356 = 5109^2 + 1434^2 .

It is not a de Polignac number, because 28158237 - 2⁶ = 28158173 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28158257) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1564338 + ... + 1564355.

It is an arithmetic number, because the mean of its divisors is an integer number (6778837).

Almost surely, 2^28158237 is an apocalyptic number.

It is an amenable number.

28158237 is a deficient number, since it is larger than the sum of its proper divisors (12514785).

28158237 is a wasteful number, since it uses less digits than its factorization.

28158237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3128699 (or 3128696 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 28158237 is about 5306.4335480622. The cubic root of 28158237 is about 304.2298476705.

The spelling of 28158237 in words is "twenty-eight million, one hundred fifty-eight thousand, two hundred thirty-seven".