28265731 has 4 divisors (see below), whose sum is σ = 30440032. Its totient is φ = 26091432.

The previous prime is 28265729. The next prime is 28265737. The reversal of 28265731 is 13756282.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13756282 = 2 ⋅6878141.

It is a cyclic number.

It is not a de Polignac number, because 28265731 - 2¹ = 28265729 is a prime.

It is a super-2 number, since 2×28265731² = 1597903097928722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28265737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1087131 + ... + 1087156.

It is an arithmetic number, because the mean of its divisors is an integer number (7610008).

Almost surely, 2^28265731 is an apocalyptic number.

28265731 is a deficient number, since it is larger than the sum of its proper divisors (2174301).

28265731 is a wasteful number, since it uses less digits than its factorization.

28265731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2174300.

The product of its digits is 20160, while the sum is 34.

The square root of 28265731 is about 5316.5525484095. The cubic root of 28265731 is about 304.6164883171.

The spelling of 28265731 in words is "twenty-eight million, two hundred sixty-five thousand, seven hundred thirty-one".