21886919 has 2 divisors, whose sum is σ = 21886920. Its totient is φ = 21886918.

The previous prime is 21886883. The next prime is 21886927. The reversal of 21886919 is 91968812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21886919 - 2⁸ = 21886663 is a prime.

It is a super-2 number, since 2×21886919² = 958074446625122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21886919.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21886979) 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, 10943459 + 10943460.

It is an arithmetic number, because the mean of its divisors is an integer number (10943460).

Almost surely, 2^21886919 is an apocalyptic number.

21886919 is a deficient number, since it is larger than the sum of its proper divisors (1).

21886919 is an equidigital number, since it uses as much as digits as its factorization.

21886919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 44.

The square root of 21886919 is about 4678.3457546445. The cubic root of 21886919 is about 279.7230211681.

The spelling of 21886919 in words is "twenty-one million, eight hundred eighty-six thousand, nine hundred nineteen".