22685821 has 2 divisors, whose sum is σ = 22685822. Its totient is φ = 22685820.

The previous prime is 22685813. The next prime is 22685857. The reversal of 22685821 is 12858622.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19263321 + 3422500 = 4389^2 + 1850^2 .

It is a cyclic number.

It is not a de Polignac number, because 22685821 - 2³ = 22685813 is a prime.

It is a super-3 number, since 3×22685821³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22685881) 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 as a sum of consecutive naturals, namely, 11342910 + 11342911.

It is an arithmetic number, because the mean of its divisors is an integer number (11342911).

Almost surely, 2^22685821 is an apocalyptic number.

It is an amenable number.

22685821 is a deficient number, since it is larger than the sum of its proper divisors (1).

22685821 is an equidigital number, since it uses as much as digits as its factorization.

22685821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15360, while the sum is 34.

The square root of 22685821 is about 4762.9634682622. The cubic root of 22685821 is about 283.0858534112.

The spelling of 22685821 in words is "twenty-two million, six hundred eighty-five thousand, eight hundred twenty-one".