28914021 has 12 divisors (see below), whose sum is σ = 41813772. Its totient is φ = 19253376.

The previous prime is 28913999. The next prime is 28914031. The reversal of 28914021 is 12041982.

It can be written as a sum of positive squares in 2 ways, for example, as 24117921 + 4796100 = 4911^2 + 2190^2 .

It is not a de Polignac number, because 28914021 - 2⁷ = 28913893 is a prime.

It is a super-2 number, since 2×28914021² = 1672041220776882, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28914031) 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 11 ways as a sum of consecutive naturals, for example, 10435 + ... + 12911.

It is an arithmetic number, because the mean of its divisors is an integer number (3484481).

Almost surely, 2^28914021 is an apocalyptic number.

It is an amenable number.

28914021 is a deficient number, since it is larger than the sum of its proper divisors (12899751).

28914021 is a wasteful number, since it uses less digits than its factorization.

28914021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3780 (or 3777 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 28914021 is about 5377.1759316578. The cubic root of 28914021 is about 306.9277558859.

The spelling of 28914021 in words is "twenty-eight million, nine hundred fourteen thousand, twenty-one".