28156197 has 16 divisors (see below), whose sum is σ = 38890368. Its totient is φ = 18108480.

The previous prime is 28156189. The next prime is 28156201. The reversal of 28156197 is 79165182.

It is not a de Polignac number, because 28156197 - 2³ = 28156189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28156127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8248 + ... + 11150.

It is an arithmetic number, because the mean of its divisors is an integer number (2430648).

Almost surely, 2^28156197 is an apocalyptic number.

It is an amenable number.

28156197 is a deficient number, since it is larger than the sum of its proper divisors (10734171).

28156197 is a wasteful number, since it uses less digits than its factorization.

28156197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3020.

The product of its digits is 30240, while the sum is 39.

The square root of 28156197 is about 5306.2413250812. The cubic root of 28156197 is about 304.2225005737. Note that the first 3 decimals are identical.

The spelling of 28156197 in words is "twenty-eight million, one hundred fifty-six thousand, one hundred ninety-seven".