21967019 has 2 divisors, whose sum is σ = 21967020. Its totient is φ = 21967018.

The previous prime is 21966961. The next prime is 21967031. The reversal of 21967019 is 91076912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21967019 - 2¹² = 21962923 is a prime.

It is a super-2 number, since 2×21967019² = 965099847492722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21967019.

It is not a weakly prime, because it can be changed into another prime (21967079) 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, 10983509 + 10983510.

It is an arithmetic number, because the mean of its divisors is an integer number (10983510).

Almost surely, 2^21967019 is an apocalyptic number.

21967019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21967019 is an equidigital number, since it uses as much as digits as its factorization.

21967019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 21967019 is about 4686.8986547609. The cubic root of 21967019 is about 280.0638417351.

The spelling of 21967019 in words is "twenty-one million, nine hundred sixty-seven thousand, nineteen".