28507639 has 2 divisors, whose sum is σ = 28507640. Its totient is φ = 28507638.

The previous prime is 28507637. The next prime is 28507643. The reversal of 28507639 is 93670582.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28507639 - 2¹ = 28507637 is a prime.

Together with 28507637, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28507637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14253819 + 14253820.

It is an arithmetic number, because the mean of its divisors is an integer number (14253820).

Almost surely, 2^28507639 is an apocalyptic number.

28507639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28507639 is an equidigital number, since it uses as much as digits as its factorization.

28507639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 28507639 is about 5339.2545359816. The cubic root of 28507639 is about 305.4830257283.

The spelling of 28507639 in words is "twenty-eight million, five hundred seven thousand, six hundred thirty-nine".