21899743 has 2 divisors, whose sum is σ = 21899744. Its totient is φ = 21899742.

The previous prime is 21899719. The next prime is 21899777. The reversal of 21899743 is 34799812.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21899743 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21899743.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21899783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10949871 + 10949872.

It is an arithmetic number, because the mean of its divisors is an integer number (10949872).

Almost surely, 2^21899743 is an apocalyptic number.

21899743 is a deficient number, since it is larger than the sum of its proper divisors (1).

21899743 is an equidigital number, since it uses as much as digits as its factorization.

21899743 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 21899743 is about 4679.7161238691. The cubic root of 21899743 is about 279.7776423424. Note that the first 3 decimals are identical.

The spelling of 21899743 in words is "twenty-one million, eight hundred ninety-nine thousand, seven hundred forty-three".