28540181 has 4 divisors (see below), whose sum is σ = 29460864. Its totient is φ = 27619500.

The previous prime is 28540163. The next prime is 28540189. The reversal of 28540181 is 18104582.

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 28540181 - 2⁶ = 28540117 is a prime.

It is a super-2 number, since 2×28540181² = 1629083863025522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28540189) 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, 460295 + ... + 460356.

It is an arithmetic number, because the mean of its divisors is an integer number (7365216).

Almost surely, 2^28540181 is an apocalyptic number.

It is an amenable number.

28540181 is a deficient number, since it is larger than the sum of its proper divisors (920683).

28540181 is an equidigital number, since it uses as much as digits as its factorization.

28540181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920682.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 28540181 is about 5342.3010959698. The cubic root of 28540181 is about 305.5992197117.

The spelling of 28540181 in words is "twenty-eight million, five hundred forty thousand, one hundred eighty-one".