21068417 has 2 divisors, whose sum is σ = 21068418. Its totient is φ = 21068416.

The previous prime is 21068357. The next prime is 21068441. The reversal of 21068417 is 71486012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13278736 + 7789681 = 3644^2 + 2791^2 .

It is a cyclic number.

It is not a de Polignac number, because 21068417 - 2¹⁶ = 21002881 is a prime.

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 21068417.

It is not a weakly prime, because it can be changed into another prime (21068477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10534208 + 10534209.

It is an arithmetic number, because the mean of its divisors is an integer number (10534209).

Almost surely, 2^21068417 is an apocalyptic number.

It is an amenable number.

21068417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21068417 is an equidigital number, since it uses as much as digits as its factorization.

21068417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21068417 is about 4590.0345314605. The cubic root of 21068417 is about 276.1917076352.

The spelling of 21068417 in words is "twenty-one million, sixty-eight thousand, four hundred seventeen".