28890997 has 2 divisors, whose sum is σ = 28890998. Its totient is φ = 28890996.

The previous prime is 28890959. The next prime is 28891021. The reversal of 28890997 is 79909882.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15634116 + 13256881 = 3954^2 + 3641^2 .

It is a cyclic number.

It is not a de Polignac number, because 28890997 - 2¹⁵ = 28858229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28890907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14445498 + 14445499.

It is an arithmetic number, because the mean of its divisors is an integer number (14445499).

Almost surely, 2^28890997 is an apocalyptic number.

It is an amenable number.

28890997 is a deficient number, since it is larger than the sum of its proper divisors (1).

28890997 is an equidigital number, since it uses as much as digits as its factorization.

28890997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 52.

The square root of 28890997 is about 5375.0346045398. The cubic root of 28890997 is about 306.8462662262.

The spelling of 28890997 in words is "twenty-eight million, eight hundred ninety thousand, nine hundred ninety-seven".