28166261 has 4 divisors (see below), whose sum is σ = 28308000. Its totient is φ = 28024524.

The previous prime is 28166249. The next prime is 28166269. The reversal of 28166261 is 16266182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28166261 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 (28166269) 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, 70571 + ... + 70968.

It is an arithmetic number, because the mean of its divisors is an integer number (7077000).

Almost surely, 2^28166261 is an apocalyptic number.

It is an amenable number.

28166261 is a deficient number, since it is larger than the sum of its proper divisors (141739).

28166261 is a wasteful number, since it uses less digits than its factorization.

28166261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141738.

The product of its digits is 6912, while the sum is 32.

The square root of 28166261 is about 5307.1895575719. The cubic root of 28166261 is about 304.2587428088.

The spelling of 28166261 in words is "twenty-eight million, one hundred sixty-six thousand, two hundred sixty-one".