28110021 has 8 divisors (see below), whose sum is σ = 37506144. Its totient is φ = 18726960.

The previous prime is 28110013. The next prime is 28110041. The reversal of 28110021 is 12001182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28110021 - 2³ = 28110013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28110001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4195 + ... + 8591.

It is an arithmetic number, because the mean of its divisors is an integer number (4688268).

Almost surely, 2^28110021 is an apocalyptic number.

It is an amenable number.

28110021 is a deficient number, since it is larger than the sum of its proper divisors (9396123).

28110021 is a wasteful number, since it uses less digits than its factorization.

28110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6531.

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 28110021 is about 5301.8884371514. Note that the first 3 decimals coincide. The cubic root of 28110021 is about 304.0561018632.

The spelling of 28110021 in words is "twenty-eight million, one hundred ten thousand, twenty-one".