21896717 has 2 divisors, whose sum is σ = 21896718. Its totient is φ = 21896716.

The previous prime is 21896681. The next prime is 21896767. The reversal of 21896717 is 71769812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17355556 + 4541161 = 4166^2 + 2131^2 .

It is a cyclic number.

It is not a de Polignac number, because 21896717 - 2¹⁶ = 21831181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21896767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10948358 + 10948359.

It is an arithmetic number, because the mean of its divisors is an integer number (10948359).

Almost surely, 2^21896717 is an apocalyptic number.

It is an amenable number.

21896717 is a deficient number, since it is larger than the sum of its proper divisors (1).

21896717 is an equidigital number, since it uses as much as digits as its factorization.

21896717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 41.

The square root of 21896717 is about 4679.3928024905. The cubic root of 21896717 is about 279.7647556441.

The spelling of 21896717 in words is "twenty-one million, eight hundred ninety-six thousand, seven hundred seventeen".