21885593 has 2 divisors, whose sum is σ = 21885594. Its totient is φ = 21885592.

The previous prime is 21885569. The next prime is 21885623. The reversal of 21885593 is 39558812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12201049 + 9684544 = 3493^2 + 3112^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21885593 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21885593.

It is not a weakly prime, because it can be changed into another prime (21885533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10942796 + 10942797.

It is an arithmetic number, because the mean of its divisors is an integer number (10942797).

Almost surely, 2^21885593 is an apocalyptic number.

It is an amenable number.

21885593 is a deficient number, since it is larger than the sum of its proper divisors (1).

21885593 is an equidigital number, since it uses as much as digits as its factorization.

21885593 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86400, while the sum is 41.

The square root of 21885593 is about 4678.2040357385. The cubic root of 21885593 is about 279.7173721285.

The spelling of 21885593 in words is "twenty-one million, eight hundred eighty-five thousand, five hundred ninety-three".