28194561 has 12 divisors (see below), whose sum is σ = 42234192. Its totient is φ = 18796212.

The previous prime is 28194557. The next prime is 28194563. The reversal of 28194561 is 16549182.

28194561 is a `hidden beast` number, since 2 + 8 + 1 + 94 + 561 = 666.

It is not a de Polignac number, because 28194561 - 2² = 28194557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28194563) 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, 57771 + ... + 58256.

It is an arithmetic number, because the mean of its divisors is an integer number (3519516).

Almost surely, 2^28194561 is an apocalyptic number.

It is an amenable number.

28194561 is a deficient number, since it is larger than the sum of its proper divisors (14039631).

28194561 is an equidigital number, since it uses as much as digits as its factorization.

28194561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116042 (or 116030 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 28194561 is about 5309.8550827683. The cubic root of 28194561 is about 304.3606098407.

The spelling of 28194561 in words is "twenty-eight million, one hundred ninety-four thousand, five hundred sixty-one".