28806989 has 2 divisors, whose sum is σ = 28806990. Its totient is φ = 28806988.

The previous prime is 28806929. The next prime is 28806991. The reversal of 28806989 is 98960882.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18852964 + 9954025 = 4342^2 + 3155^2 .

It is a cyclic number.

It is not a de Polignac number, because 28806989 - 2⁸ = 28806733 is a prime.

It is a super-2 number, since 2×28806989² = 1659685230492242, which contains 22 as substring.

Together with 28806991, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28806919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14403494 + 14403495.

It is an arithmetic number, because the mean of its divisors is an integer number (14403495).

Almost surely, 2^28806989 is an apocalyptic number.

It is an amenable number.

28806989 is a deficient number, since it is larger than the sum of its proper divisors (1).

28806989 is an equidigital number, since it uses as much as digits as its factorization.

28806989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 497664, while the sum is 50.

The square root of 28806989 is about 5367.2142681283. The cubic root of 28806989 is about 306.5485660289.

The spelling of 28806989 in words is "twenty-eight million, eight hundred six thousand, nine hundred eighty-nine".