21796717 has 2 divisors, whose sum is σ = 21796718. Its totient is φ = 21796716.

The previous prime is 21796711. The next prime is 21796739. The reversal of 21796717 is 71769712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13205956 + 8590761 = 3634^2 + 2931^2 .

It is a cyclic number.

It is not a de Polignac number, because 21796717 - 2¹⁹ = 21272429 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21796717.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21796711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10898358 + 10898359.

It is an arithmetic number, because the mean of its divisors is an integer number (10898359).

Almost surely, 2^21796717 is an apocalyptic number.

It is an amenable number.

21796717 is a deficient number, since it is larger than the sum of its proper divisors (1).

21796717 is an equidigital number, since it uses as much as digits as its factorization.

21796717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37044, while the sum is 40.

The square root of 21796717 is about 4668.6954280612. The cubic root of 21796717 is about 279.3382202798.

The spelling of 21796717 in words is "twenty-one million, seven hundred ninety-six thousand, seven hundred seventeen".