28197831 has 8 divisors (see below), whose sum is σ = 38893680. Its totient is φ = 18150272.

The previous prime is 28197779. The next prime is 28197833. The reversal of 28197831 is 13879182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28197831 - 2¹⁹ = 27673543 is a prime.

It is a super-2 number, since 2×28197831² = 1590235346209122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28197831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28197833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161970 + ... + 162143.

It is an arithmetic number, because the mean of its divisors is an integer number (4861710).

Almost surely, 2^28197831 is an apocalyptic number.

28197831 is a deficient number, since it is larger than the sum of its proper divisors (10695849).

28197831 is a wasteful number, since it uses less digits than its factorization.

28197831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324145.

The product of its digits is 24192, while the sum is 39.

The square root of 28197831 is about 5310.1629918487. The cubic root of 28197831 is about 304.3723759484.

The spelling of 28197831 in words is "twenty-eight million, one hundred ninety-seven thousand, eight hundred thirty-one".