21702719 has 2 divisors, whose sum is σ = 21702720. Its totient is φ = 21702718.

The previous prime is 21702679. The next prime is 21702809. The reversal of 21702719 is 91720712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21702719 - 2¹² = 21698623 is a prime.

It is a super-2 number, since 2×21702719² = 942016023985922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21702691 and 21702700.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21702419) 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, 10851359 + 10851360.

It is an arithmetic number, because the mean of its divisors is an integer number (10851360).

Almost surely, 2^21702719 is an apocalyptic number.

21702719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21702719 is an equidigital number, since it uses as much as digits as its factorization.

21702719 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 21702719 is about 4658.6177134425. The cubic root of 21702719 is about 278.9360944405.

The spelling of 21702719 in words is "twenty-one million, seven hundred two thousand, seven hundred nineteen".