28386397 has 4 divisors (see below), whose sum is σ = 30569980. Its totient is φ = 26202816.

The previous prime is 28386367. The next prime is 28386401. The reversal of 28386397 is 79368382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79368382 = 2 ⋅39684191.

It can be written as a sum of positive squares in 2 ways, for example, as 7901721 + 20484676 = 2811^2 + 4526^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28386397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28386307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1091772 + ... + 1091797.

It is an arithmetic number, because the mean of its divisors is an integer number (7642495).

Almost surely, 2^28386397 is an apocalyptic number.

It is an amenable number.

28386397 is a deficient number, since it is larger than the sum of its proper divisors (2183583).

28386397 is a wasteful number, since it uses less digits than its factorization.

28386397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2183582.

The product of its digits is 435456, while the sum is 46.

The square root of 28386397 is about 5327.8886061929. Note that the first 3 decimals coincide. The cubic root of 28386397 is about 305.0493407589.

The spelling of 28386397 in words is "twenty-eight million, three hundred eighty-six thousand, three hundred ninety-seven".