21619711 has 2 divisors, whose sum is σ = 21619712. Its totient is φ = 21619710.

The previous prime is 21619709. The next prime is 21619721. The reversal of 21619711 is 11791612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21619711 - 2¹ = 21619709 is a prime.

Together with 21619709, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21619711.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21619721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10809855 + 10809856.

It is an arithmetic number, because the mean of its divisors is an integer number (10809856).

Almost surely, 2^21619711 is an apocalyptic number.

21619711 is a deficient number, since it is larger than the sum of its proper divisors (1).

21619711 is an equidigital number, since it uses as much as digits as its factorization.

21619711 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756, while the sum is 28.

The square root of 21619711 is about 4649.7000978558. The cubic root of 21619711 is about 278.5800175555.

The spelling of 21619711 in words is "twenty-one million, six hundred nineteen thousand, seven hundred eleven".