21965719 has 2 divisors, whose sum is σ = 21965720. Its totient is φ = 21965718.

The previous prime is 21965707. The next prime is 21965737. The reversal of 21965719 is 91756912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21965719 - 2¹¹ = 21963671 is a prime.

It is a super-2 number, since 2×21965719² = 964985622373922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21965219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10982859 + 10982860.

It is an arithmetic number, because the mean of its divisors is an integer number (10982860).

Almost surely, 2^21965719 is an apocalyptic number.

21965719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21965719 is an equidigital number, since it uses as much as digits as its factorization.

21965719 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 40.

The square root of 21965719 is about 4686.7599682510. The cubic root of 21965719 is about 280.0583169348.

The spelling of 21965719 in words is "twenty-one million, nine hundred sixty-five thousand, seven hundred nineteen".