28775139 has 32 divisors (see below), whose sum is σ = 43130880. Its totient is φ = 16977312.

The previous prime is 28775129. The next prime is 28775141. The reversal of 28775139 is 93157782.

It is not a de Polignac number, because 28775139 - 2⁵ = 28775107 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28775139.

It is not an unprimeable number, because it can be changed into a prime (28775129) 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, 61384 + ... + 61850.

It is an arithmetic number, because the mean of its divisors is an integer number (1347840).

Almost surely, 2^28775139 is an apocalyptic number.

28775139 is a deficient number, since it is larger than the sum of its proper divisors (14355741).

28775139 is a wasteful number, since it uses less digits than its factorization.

28775139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559.

The product of its digits is 105840, while the sum is 42.

The square root of 28775139 is about 5364.2463589958. The cubic root of 28775139 is about 306.4355474792.

The spelling of 28775139 in words is "twenty-eight million, seven hundred seventy-five thousand, one hundred thirty-nine".