28227731 has 4 divisors (see below), whose sum is σ = 32260272. Its totient is φ = 24195192.

The previous prime is 28227709. The next prime is 28227733. The reversal of 28227731 is 13772282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13772282 = 2 ⋅6886141.

It is a de Polignac number, because none of the positive numbers 2^k-28227731 is a prime.

It is a super-2 number, since 2×28227731² = 1593609594816722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28227733) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2016260 + ... + 2016273.

It is an arithmetic number, because the mean of its divisors is an integer number (8065068).

Almost surely, 2^28227731 is an apocalyptic number.

28227731 is a deficient number, since it is larger than the sum of its proper divisors (4032541).

28227731 is an equidigital number, since it uses as much as digits as its factorization.

28227731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4032540.

The product of its digits is 9408, while the sum is 32.

The square root of 28227731 is about 5312.9776020608. The cubic root of 28227731 is about 304.4799199085.

The spelling of 28227731 in words is "twenty-eight million, two hundred twenty-seven thousand, seven hundred thirty-one".