28239361 has 4 divisors (see below), whose sum is σ = 28660912. Its totient is φ = 27817812.

The previous prime is 28239353. The next prime is 28239373. The reversal of 28239361 is 16393282.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16393282 = 2 ⋅8196641.

It is a cyclic number.

It is not a de Polignac number, because 28239361 - 2³ = 28239353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28239391) 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, 210675 + ... + 210808.

It is an arithmetic number, because the mean of its divisors is an integer number (7165228).

Almost surely, 2^28239361 is an apocalyptic number.

It is an amenable number.

28239361 is a deficient number, since it is larger than the sum of its proper divisors (421551).

28239361 is an equidigital number, since it uses as much as digits as its factorization.

28239361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421550.

The product of its digits is 15552, while the sum is 34.

The square root of 28239361 is about 5314.0719791888. The cubic root of 28239361 is about 304.5217300379.

The spelling of 28239361 in words is "twenty-eight million, two hundred thirty-nine thousand, three hundred sixty-one".