21586589 has 2 divisors, whose sum is σ = 21586590. Its totient is φ = 21586588.

The previous prime is 21586567. The next prime is 21586597. The reversal of 21586589 is 98568512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12180100 + 9406489 = 3490^2 + 3067^2 .

It is a cyclic number.

It is not a de Polignac number, because 21586589 - 2¹² = 21582493 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21586519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10793294 + 10793295.

It is an arithmetic number, because the mean of its divisors is an integer number (10793295).

Almost surely, 2^21586589 is an apocalyptic number.

It is an amenable number.

21586589 is a deficient number, since it is larger than the sum of its proper divisors (1).

21586589 is an equidigital number, since it uses as much as digits as its factorization.

21586589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 44.

The square root of 21586589 is about 4646.1369975497. The cubic root of 21586589 is about 278.4376807249.

The spelling of 21586589 in words is "twenty-one million, five hundred eighty-six thousand, five hundred eighty-nine".