21159211 has 2 divisors, whose sum is σ = 21159212. Its totient is φ = 21159210.

The previous prime is 21159181. The next prime is 21159221. The reversal of 21159211 is 11295112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21159211 - 2²¹ = 19062059 is a prime.

It is not a weakly prime, because it can be changed into another prime (21159221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10579605 + 10579606.

It is an arithmetic number, because the mean of its divisors is an integer number (10579606).

Almost surely, 2^21159211 is an apocalyptic number.

21159211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21159211 is an equidigital number, since it uses as much as digits as its factorization.

21159211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 180, while the sum is 22.

The square root of 21159211 is about 4599.9142383310. The cubic root of 21159211 is about 276.5878869585.

The spelling of 21159211 in words is "twenty-one million, one hundred fifty-nine thousand, two hundred eleven".