28889639 has 2 divisors, whose sum is σ = 28889640. Its totient is φ = 28889638.

The previous prime is 28889617. The next prime is 28889683. The reversal of 28889639 is 93698882.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28889639 - 2⁸ = 28889383 is a prime.

It is a super-2 number, since 2×28889639² = 1669222483100642, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28889689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14444819 + 14444820.

It is an arithmetic number, because the mean of its divisors is an integer number (14444820).

Almost surely, 2^28889639 is an apocalyptic number.

28889639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28889639 is an equidigital number, since it uses as much as digits as its factorization.

28889639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1492992, while the sum is 53.

The square root of 28889639 is about 5374.9082782872. The cubic root of 28889639 is about 306.8414584567.

The spelling of 28889639 in words is "twenty-eight million, eight hundred eighty-nine thousand, six hundred thirty-nine".