28158161 has 4 divisors (see below), whose sum is σ = 28291824. Its totient is φ = 28024500.

The previous prime is 28158083. The next prime is 28158173. The reversal of 28158161 is 16185182.

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 not a de Polignac number, because 28158161 - 2¹⁰ = 28157137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28158181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66515 + ... + 66936.

It is an arithmetic number, because the mean of its divisors is an integer number (7072956).

Almost surely, 2^28158161 is an apocalyptic number.

It is an amenable number.

28158161 is a deficient number, since it is larger than the sum of its proper divisors (133663).

28158161 is a wasteful number, since it uses less digits than its factorization.

28158161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133662.

The product of its digits is 3840, while the sum is 32.

The square root of 28158161 is about 5306.4263869388. The cubic root of 28158161 is about 304.2295739615.

The spelling of 28158161 in words is "twenty-eight million, one hundred fifty-eight thousand, one hundred sixty-one".