28569391 has 2 divisors, whose sum is σ = 28569392. Its totient is φ = 28569390.

The previous prime is 28569389. The next prime is 28569413. The reversal of 28569391 is 19396582.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28569391 - 2¹ = 28569389 is a prime.

It is a super-2 number, since 2×28569391² = 1632420204221762, which contains 22 as substring.

Together with 28569389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28569301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14284695 + 14284696.

It is an arithmetic number, because the mean of its divisors is an integer number (14284696).

Almost surely, 2^28569391 is an apocalyptic number.

28569391 is a deficient number, since it is larger than the sum of its proper divisors (1).

28569391 is an equidigital number, since it uses as much as digits as its factorization.

28569391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 43.

The square root of 28569391 is about 5345.0342374956. The cubic root of 28569391 is about 305.7034413071.

The spelling of 28569391 in words is "twenty-eight million, five hundred sixty-nine thousand, three hundred ninety-one".