28206397 has 12 divisors (see below), whose sum is σ = 29392320. Its totient is φ = 27057888.

The previous prime is 28206389. The next prime is 28206403. The reversal of 28206397 is 79360282.

It is not a de Polignac number, because 28206397 - 2³ = 28206389 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 (28206337) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 357004 + ... + 357082.

It is an arithmetic number, because the mean of its divisors is an integer number (2449360).

Almost surely, 2^28206397 is an apocalyptic number.

It is an amenable number.

28206397 is a deficient number, since it is larger than the sum of its proper divisors (1185923).

28206397 is an frugal number, since it uses more digits than its factorization.

28206397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 28206397 is about 5310.9694971822. The cubic root of 28206397 is about 304.4031938011.

The spelling of 28206397 in words is "twenty-eight million, two hundred six thousand, three hundred ninety-seven".