28057239 has 32 divisors (see below), whose sum is σ = 49152000. Its totient is φ = 15476832.

The previous prime is 28057231. The next prime is 28057241. The reversal of 28057239 is 93275082.

It is a happy number.

28057239 is a `hidden beast` number, since 2 + 80 + 572 + 3 + 9 = 666.

It is not a de Polignac number, because 28057239 - 2³ = 28057231 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28057231) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2922 + ... + 8040.

It is an arithmetic number, because the mean of its divisors is an integer number (1536000).

Almost surely, 2^28057239 is an apocalyptic number.

28057239 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

28057239 is a deficient number, since it is larger than the sum of its proper divisors (21094761).

28057239 is a wasteful number, since it uses less digits than its factorization.

28057239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5164 (or 5158 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 28057239 is about 5296.9084379476. The cubic root of 28057239 is about 303.8656745835.

The spelling of 28057239 in words is "twenty-eight million, fifty-seven thousand, two hundred thirty-nine".