28421181 has 12 divisors (see below), whose sum is σ = 41726620. Its totient is φ = 18636480.

The previous prime is 28421167. The next prime is 28421209. The reversal of 28421181 is 18112482.

It can be written as a sum of positive squares in 2 ways, for example, as 6937956 + 21483225 = 2634^2 + 4635^2 .

It is not a de Polignac number, because 28421181 - 2⁵ = 28421149 is a prime.

It is a super-2 number, since 2×28421181² = 1615527058869522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28421101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25336 + ... + 26433.

Almost surely, 2^28421181 is an apocalyptic number.

It is an amenable number.

28421181 is a deficient number, since it is larger than the sum of its proper divisors (13305439).

28421181 is a wasteful number, since it uses less digits than its factorization.

28421181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51836 (or 51833 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 28421181 is about 5331.1519393092. The cubic root of 28421181 is about 305.1738899122.

The spelling of 28421181 in words is "twenty-eight million, four hundred twenty-one thousand, one hundred eighty-one".