28815091 has 2 divisors, whose sum is σ = 28815092. Its totient is φ = 28815090.

The previous prime is 28815079. The next prime is 28815107. The reversal of 28815091 is 19051882.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28815091 - 2⁹ = 28814579 is a prime.

It is not a weakly prime, because it can be changed into another prime (28815491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14407545 + 14407546.

It is an arithmetic number, because the mean of its divisors is an integer number (14407546).

Almost surely, 2^28815091 is an apocalyptic number.

28815091 is a deficient number, since it is larger than the sum of its proper divisors (1).

28815091 is an equidigital number, since it uses as much as digits as its factorization.

28815091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 28815091 is about 5367.9689827718. The cubic root of 28815091 is about 306.5773023850.

The spelling of 28815091 in words is "twenty-eight million, eight hundred fifteen thousand, ninety-one".