28168961 has 4 divisors (see below), whose sum is σ = 28270932. Its totient is φ = 28066992.

The previous prime is 28168939. The next prime is 28168967. The reversal of 28168961 is 16986182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6031936 + 22137025 = 2456^2 + 4705^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28168961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28168967) 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, 50570 + ... + 51123.

It is an arithmetic number, because the mean of its divisors is an integer number (7067733).

Almost surely, 2^28168961 is an apocalyptic number.

It is an amenable number.

28168961 is a deficient number, since it is larger than the sum of its proper divisors (101971).

28168961 is a wasteful number, since it uses less digits than its factorization.

28168961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101970.

The product of its digits is 41472, while the sum is 41.

The square root of 28168961 is about 5307.4439233966. The cubic root of 28168961 is about 304.2684645151.

The spelling of 28168961 in words is "twenty-eight million, one hundred sixty-eight thousand, nine hundred sixty-one".