28186901 has 4 divisors (see below), whose sum is σ = 29844972. Its totient is φ = 26528832.

The previous prime is 28186889. The next prime is 28186913. The reversal of 28186901 is 10968182.

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

It is an interprime number because it is at equal distance from previous prime (28186889) and next prime (28186913).

It can be written as a sum of positive squares in 2 ways, for example, as 10956100 + 17230801 = 3310^2 + 4151^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28186901 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 (28186931) 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, 829010 + ... + 829043.

It is an arithmetic number, because the mean of its divisors is an integer number (7461243).

Almost surely, 2^28186901 is an apocalyptic number.

It is an amenable number.

28186901 is a deficient number, since it is larger than the sum of its proper divisors (1658071).

28186901 is a wasteful number, since it uses less digits than its factorization.

28186901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1658070.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 28186901 is about 5309.1337334823. The cubic root of 28186901 is about 304.3330440815. Note that the first 3 decimals are identical.

The spelling of 28186901 in words is "twenty-eight million, one hundred eighty-six thousand, nine hundred one".