28391197 has 2 divisors, whose sum is σ = 28391198. Its totient is φ = 28391196.

The previous prime is 28391189. The next prime is 28391227. The reversal of 28391197 is 79119382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23677956 + 4713241 = 4866^2 + 2171^2 .

It is a cyclic number.

It is not a de Polignac number, because 28391197 - 2³ = 28391189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28391107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14195598 + 14195599.

It is an arithmetic number, because the mean of its divisors is an integer number (14195599).

Almost surely, 2^28391197 is an apocalyptic number.

It is an amenable number.

28391197 is a deficient number, since it is larger than the sum of its proper divisors (1).

28391197 is an equidigital number, since it uses as much as digits as its factorization.

28391197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 40.

The square root of 28391197 is about 5328.3390470202. The cubic root of 28391197 is about 305.0665339039.

The spelling of 28391197 in words is "twenty-eight million, three hundred ninety-one thousand, one hundred ninety-seven".