28196989 has 2 divisors, whose sum is σ = 28196990. Its totient is φ = 28196988.

The previous prime is 28196963. The next prime is 28197031. The reversal of 28196989 is 98969182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19873764 + 8323225 = 4458^2 + 2885^2 .

It is a cyclic number.

It is not a de Polignac number, because 28196989 - 2¹⁵ = 28164221 is a prime.

It is a super-2 number, since 2×28196989² = 1590140377332242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28116989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14098494 + 14098495.

It is an arithmetic number, because the mean of its divisors is an integer number (14098495).

Almost surely, 2^28196989 is an apocalyptic number.

It is an amenable number.

28196989 is a deficient number, since it is larger than the sum of its proper divisors (1).

28196989 is an equidigital number, since it uses as much as digits as its factorization.

28196989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 52.

The square root of 28196989 is about 5310.0837093214. The cubic root of 28196989 is about 304.3693463526.

The spelling of 28196989 in words is "twenty-eight million, one hundred ninety-six thousand, nine hundred eighty-nine".