21585133 has 2 divisors, whose sum is σ = 21585134. Its totient is φ = 21585132.

The previous prime is 21585127. The next prime is 21585139. The reversal of 21585133 is 33158512.

It is a balanced prime because it is at equal distance from previous prime (21585127) and next prime (21585139).

It can be written as a sum of positive squares in only one way, i.e., 18688329 + 2896804 = 4323^2 + 1702^2 .

It is a cyclic number.

It is not a de Polignac number, because 21585133 - 2¹³ = 21576941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21585139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10792566 + 10792567.

It is an arithmetic number, because the mean of its divisors is an integer number (10792567).

Almost surely, 2^21585133 is an apocalyptic number.

It is an amenable number.

21585133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21585133 is an equidigital number, since it uses as much as digits as its factorization.

21585133 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 28.

The square root of 21585133 is about 4645.9803055975. The cubic root of 21585133 is about 278.4314204433.

The spelling of 21585133 in words is "twenty-one million, five hundred eighty-five thousand, one hundred thirty-three".