28807139 has 2 divisors, whose sum is σ = 28807140. Its totient is φ = 28807138.

The previous prime is 28807081. The next prime is 28807147. The reversal of 28807139 is 93170882.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28807139 - 2¹² = 28803043 is a prime.

It is a Chen prime.

It is equal to p_1788455 and since 28807139 and 1788455 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (28807039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14403569 + 14403570.

It is an arithmetic number, because the mean of its divisors is an integer number (14403570).

Almost surely, 2^28807139 is an apocalyptic number.

28807139 is a deficient number, since it is larger than the sum of its proper divisors (1).

28807139 is an equidigital number, since it uses as much as digits as its factorization.

28807139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 28807139 is about 5367.2282418395. The cubic root of 28807139 is about 306.5490981013.

The spelling of 28807139 in words is "twenty-eight million, eight hundred seven thousand, one hundred thirty-nine".