28190389 has 2 divisors, whose sum is σ = 28190390. Its totient is φ = 28190388.

The previous prime is 28190381. The next prime is 28190419. The reversal of 28190389 is 98309182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17497489 + 10692900 = 4183^2 + 3270^2 .

It is a cyclic number.

It is not a de Polignac number, because 28190389 - 2³ = 28190381 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28190381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14095194 + 14095195.

It is an arithmetic number, because the mean of its divisors is an integer number (14095195).

Almost surely, 2^28190389 is an apocalyptic number.

It is an amenable number.

28190389 is a deficient number, since it is larger than the sum of its proper divisors (1).

28190389 is an equidigital number, since it uses as much as digits as its factorization.

28190389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 28190389 is about 5309.4622138217. The cubic root of 28190389 is about 304.3455968376.

The spelling of 28190389 in words is "twenty-eight million, one hundred ninety thousand, three hundred eighty-nine".