21916847 has 2 divisors, whose sum is σ = 21916848. Its totient is φ = 21916846.

The previous prime is 21916793. The next prime is 21916871. The reversal of 21916847 is 74861912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21916847 - 2¹⁰ = 21915823 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21916847.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21916877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10958423 + 10958424.

It is an arithmetic number, because the mean of its divisors is an integer number (10958424).

Almost surely, 2^21916847 is an apocalyptic number.

21916847 is a deficient number, since it is larger than the sum of its proper divisors (1).

21916847 is an equidigital number, since it uses as much as digits as its factorization.

21916847 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 38.

The square root of 21916847 is about 4681.5432284664. The cubic root of 21916847 is about 279.8504601153.

The spelling of 21916847 in words is "twenty-one million, nine hundred sixteen thousand, eight hundred forty-seven".