28308739 has 2 divisors, whose sum is σ = 28308740. Its totient is φ = 28308738.

The previous prime is 28308733. The next prime is 28308767. The reversal of 28308739 is 93780382.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28308739 is a prime.

It is not a weakly prime, because it can be changed into another prime (28308733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14154369 + 14154370.

It is an arithmetic number, because the mean of its divisors is an integer number (14154370).

Almost surely, 2^28308739 is an apocalyptic number.

28308739 is a deficient number, since it is larger than the sum of its proper divisors (1).

28308739 is an equidigital number, since it uses as much as digits as its factorization.

28308739 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 28308739 is about 5320.5957373212. The cubic root of 28308739 is about 304.7709074253.

The spelling of 28308739 in words is "twenty-eight million, three hundred eight thousand, seven hundred thirty-nine".