28990891 has 2 divisors, whose sum is σ = 28990892. Its totient is φ = 28990890.

The previous prime is 28990877. The next prime is 28990909. The reversal of 28990891 is 19809982.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28990891 is a prime.

It is not a weakly prime, because it can be changed into another prime (28990811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14495445 + 14495446.

It is an arithmetic number, because the mean of its divisors is an integer number (14495446).

Almost surely, 2^28990891 is an apocalyptic number.

28990891 is a deficient number, since it is larger than the sum of its proper divisors (1).

28990891 is an equidigital number, since it uses as much as digits as its factorization.

28990891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 46.

The square root of 28990891 is about 5384.3189912931. The cubic root of 28990891 is about 307.1995116897.

The spelling of 28990891 in words is "twenty-eight million, nine hundred ninety thousand, eight hundred ninety-one".