28227391 has 4 divisors (see below), whose sum is σ = 29137984. Its totient is φ = 27316800.

The previous prime is 28227383. The next prime is 28227413. The reversal of 28227391 is 19372282.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28227391 - 2³ = 28227383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28227091) 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, 455250 + ... + 455311.

It is an arithmetic number, because the mean of its divisors is an integer number (7284496).

Almost surely, 2^28227391 is an apocalyptic number.

28227391 is a deficient number, since it is larger than the sum of its proper divisors (910593).

28227391 is an equidigital number, since it uses as much as digits as its factorization.

28227391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910592.

The product of its digits is 12096, while the sum is 34.

The square root of 28227391 is about 5312.9456048411. The cubic root of 28227391 is about 304.4786974275.

The spelling of 28227391 in words is "twenty-eight million, two hundred twenty-seven thousand, three hundred ninety-one".