28012639 has 2 divisors, whose sum is σ = 28012640. Its totient is φ = 28012638.

The previous prime is 28012627. The next prime is 28012667. The reversal of 28012639 is 93621082.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28012639 - 2⁷ = 28012511 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28012639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28012619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14006319 + 14006320.

It is an arithmetic number, because the mean of its divisors is an integer number (14006320).

Almost surely, 2^28012639 is an apocalyptic number.

28012639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28012639 is an equidigital number, since it uses as much as digits as its factorization.

28012639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 28012639 is about 5292.6967606316. The cubic root of 28012639 is about 303.7045801337.

The spelling of 28012639 in words is "twenty-eight million, twelve thousand, six hundred thirty-nine".