28166549 has 4 divisors (see below), whose sum is σ = 28853580. Its totient is φ = 27479520.

The previous prime is 28166527. The next prime is 28166561. The reversal of 28166549 is 94566182.

It is a happy number.

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 5793649 + 22372900 = 2407^2 + 4730^2 .

It is a cyclic number.

It is not a de Polignac number, because 28166549 - 2⁸ = 28166293 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 686989 = 28166549 / (2 + 8 + 1 + 6 + 6 + 5 + 4 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28166519) 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, 343454 + ... + 343535.

It is an arithmetic number, because the mean of its divisors is an integer number (7213395).

Almost surely, 2^28166549 is an apocalyptic number.

It is an amenable number.

28166549 is a deficient number, since it is larger than the sum of its proper divisors (687031).

28166549 is an equidigital number, since it uses as much as digits as its factorization.

28166549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687030.

The product of its digits is 103680, while the sum is 41.

The square root of 28166549 is about 5307.2166905074. The cubic root of 28166549 is about 304.2597798204.

The spelling of 28166549 in words is "twenty-eight million, one hundred sixty-six thousand, five hundred forty-nine".