21586963 has 2 divisors, whose sum is σ = 21586964. Its totient is φ = 21586962.

The previous prime is 21586937. The next prime is 21586967. The reversal of 21586963 is 36968512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21586963 - 2¹⁷ = 21455891 is a prime.

It is not a weakly prime, because it can be changed into another prime (21586967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10793481 + 10793482.

It is an arithmetic number, because the mean of its divisors is an integer number (10793482).

Almost surely, 2^21586963 is an apocalyptic number.

21586963 is a deficient number, since it is larger than the sum of its proper divisors (1).

21586963 is an equidigital number, since it uses as much as digits as its factorization.

21586963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 40.

The square root of 21586963 is about 4646.1772458657. The cubic root of 21586963 is about 278.4392887463.

It can be divided in two parts, 215 and 86963, that added together give a palindrome (87178).

The spelling of 21586963 in words is "twenty-one million, five hundred eighty-six thousand, nine hundred sixty-three".