28333891 has 2 divisors, whose sum is σ = 28333892. Its totient is φ = 28333890.

The previous prime is 28333889. The next prime is 28333901. The reversal of 28333891 is 19833382.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28333891 - 2¹ = 28333889 is a prime.

Together with 28333889, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 28333891.

It is not a weakly prime, because it can be changed into another prime (28333871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14166945 + 14166946.

It is an arithmetic number, because the mean of its divisors is an integer number (14166946).

Almost surely, 2^28333891 is an apocalyptic number.

28333891 is a deficient number, since it is larger than the sum of its proper divisors (1).

28333891 is an equidigital number, since it uses as much as digits as its factorization.

28333891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 28333891 is about 5322.9588576280. The cubic root of 28333891 is about 304.8611425610.

It can be divided in two parts, 2833389 and 1, that added together give a triangular number (2833390 = T₂₃₈₀).

The spelling of 28333891 in words is "twenty-eight million, three hundred thirty-three thousand, eight hundred ninety-one".