28316989 has 2 divisors, whose sum is σ = 28316990. Its totient is φ = 28316988.

The previous prime is 28316987. The next prime is 28317007. The reversal of 28316989 is 98961382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27144100 + 1172889 = 5210^2 + 1083^2 .

It is a cyclic number.

It is not a de Polignac number, because 28316989 - 2¹ = 28316987 is a prime.

It is a super-2 number, since 2×28316989² = 1603703732052242, which contains 22 as substring.

Together with 28316987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28316987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14158494 + 14158495.

It is an arithmetic number, because the mean of its divisors is an integer number (14158495).

Almost surely, 2^28316989 is an apocalyptic number.

It is an amenable number.

28316989 is a deficient number, since it is larger than the sum of its proper divisors (1).

28316989 is an equidigital number, since it uses as much as digits as its factorization.

28316989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 46.

The square root of 28316989 is about 5321.3709699663. The cubic root of 28316989 is about 304.8005109548.

The spelling of 28316989 in words is "twenty-eight million, three hundred sixteen thousand, nine hundred eighty-nine".