28228131 has 24 divisors (see below), whose sum is σ = 42076944. Its totient is φ = 18224640.

The previous prime is 28228127. The next prime is 28228133. The reversal of 28228131 is 13182282.

It is not a de Polignac number, because 28228131 - 2² = 28228127 is a prime.

It is a super-2 number, since 2×28228131² = 1593654759506322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28228095 and 28228104.

It is not an unprimeable number, because it can be changed into a prime (28228133) 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, 83595 + ... + 83931.

It is an arithmetic number, because the mean of its divisors is an integer number (1753206).

Almost surely, 2^28228131 is an apocalyptic number.

28228131 is a deficient number, since it is larger than the sum of its proper divisors (13848813).

28228131 is a wasteful number, since it uses less digits than its factorization.

28228131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611 (or 608 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 28228131 is about 5313.0152456021. The cubic root of 28228131 is about 304.4813581087.

The spelling of 28228131 in words is "twenty-eight million, two hundred twenty-eight thousand, one hundred thirty-one".