28890091 has 2 divisors, whose sum is σ = 28890092. Its totient is φ = 28890090.

The previous prime is 28890079. The next prime is 28890097. The reversal of 28890091 is 19009882.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28890091 - 2⁷ = 28889963 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28890091.

It is not a weakly prime, because it can be changed into another prime (28890097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14445045 + 14445046.

It is an arithmetic number, because the mean of its divisors is an integer number (14445046).

Almost surely, 2^28890091 is an apocalyptic number.

28890091 is a deficient number, since it is larger than the sum of its proper divisors (1).

28890091 is an equidigital number, since it uses as much as digits as its factorization.

28890091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 28890091 is about 5374.9503253519. The cubic root of 28890091 is about 306.8430587030.

The spelling of 28890091 in words is "twenty-eight million, eight hundred ninety thousand, ninety-one".