21415211 has 2 divisors, whose sum is σ = 21415212. Its totient is φ = 21415210.

The previous prime is 21415187. The next prime is 21415213. The reversal of 21415211 is 11251412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21415211 - 2¹⁴ = 21398827 is a prime.

It is a super-2 number, since 2×21415211² = 917222524349042, which contains 22 as substring.

Together with 21415213, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21415211.

It is not a weakly prime, because it can be changed into another prime (21415213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10707605 + 10707606.

It is an arithmetic number, because the mean of its divisors is an integer number (10707606).

Almost surely, 2^21415211 is an apocalyptic number.

21415211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21415211 is an equidigital number, since it uses as much as digits as its factorization.

21415211 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80, while the sum is 17.

The square root of 21415211 is about 4627.6571826357. The cubic root of 21415211 is about 277.6988742946.

Adding to 21415211 its reverse (11251412), we get a palindrome (32666623).

The spelling of 21415211 in words is "twenty-one million, four hundred fifteen thousand, two hundred eleven".