28536021 has 6 divisors (see below), whose sum is σ = 41218710. Its totient is φ = 19024008.

The previous prime is 28536019. The next prime is 28536049. The reversal of 28536021 is 12063582.

28536021 is a `hidden beast` number, since 2 + 8 + 53 + 602 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 27973521 + 562500 = 5289^2 + 750^2 .

It is not a de Polignac number, because 28536021 - 2¹ = 28536019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28536061) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1585326 + ... + 1585343.

It is an arithmetic number, because the mean of its divisors is an integer number (6869785).

Almost surely, 2^28536021 is an apocalyptic number.

It is an amenable number.

28536021 is a deficient number, since it is larger than the sum of its proper divisors (12682689).

28536021 is a wasteful number, since it uses less digits than its factorization.

28536021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3170675 (or 3170672 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 28536021 is about 5341.9117364479. The cubic root of 28536021 is about 305.5843710027.

The spelling of 28536021 in words is "twenty-eight million, five hundred thirty-six thousand, twenty-one".