21365411 has 2 divisors, whose sum is σ = 21365412. Its totient is φ = 21365410.

The previous prime is 21365363. The next prime is 21365419. The reversal of 21365411 is 11456312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21365411 - 2⁶ = 21365347 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21365419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682705 + 10682706.

It is an arithmetic number, because the mean of its divisors is an integer number (10682706).

Almost surely, 2^21365411 is an apocalyptic number.

21365411 is a deficient number, since it is larger than the sum of its proper divisors (1).

21365411 is an equidigital number, since it uses as much as digits as its factorization.

21365411 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 23.

The square root of 21365411 is about 4622.2733584244. The cubic root of 21365411 is about 277.4834489493.

Subtracting from 21365411 its reverse (11456312), we obtain a palindrome (9909099).

The spelling of 21365411 in words is "twenty-one million, three hundred sixty-five thousand, four hundred eleven".