21217193 has 2 divisors, whose sum is σ = 21217194. Its totient is φ = 21217192.

The previous prime is 21217187. The next prime is 21217199. The reversal of 21217193 is 39171212.

It is a balanced prime because it is at equal distance from previous prime (21217187) and next prime (21217199).

It can be written as a sum of positive squares in only one way, i.e., 21187609 + 29584 = 4603^2 + 172^2 .

It is a cyclic number.

It is not a de Polignac number, because 21217193 - 2¹² = 21213097 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21217199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10608596 + 10608597.

It is an arithmetic number, because the mean of its divisors is an integer number (10608597).

Almost surely, 2^21217193 is an apocalyptic number.

It is an amenable number.

21217193 is a deficient number, since it is larger than the sum of its proper divisors (1).

21217193 is an equidigital number, since it uses as much as digits as its factorization.

21217193 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756, while the sum is 26.

The square root of 21217193 is about 4606.2124353964. The cubic root of 21217193 is about 276.8402985824.

The spelling of 21217193 in words is "twenty-one million, two hundred seventeen thousand, one hundred ninety-three".