21994849 has 2 divisors, whose sum is σ = 21994850. Its totient is φ = 21994848.

The previous prime is 21994829. The next prime is 21994867. The reversal of 21994849 is 94849912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16851025 + 5143824 = 4105^2 + 2268^2 .

It is a cyclic number.

It is not a de Polignac number, because 21994849 - 2¹¹ = 21992801 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21994799 and 21994808.

It is not a weakly prime, because it can be changed into another prime (21994829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10997424 + 10997425.

It is an arithmetic number, because the mean of its divisors is an integer number (10997425).

Almost surely, 2^21994849 is an apocalyptic number.

It is an amenable number.

21994849 is a deficient number, since it is larger than the sum of its proper divisors (1).

21994849 is an equidigital number, since it uses as much as digits as its factorization.

21994849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 46.

The square root of 21994849 is about 4689.8666292337. The cubic root of 21994849 is about 280.1820627152.

The spelling of 21994849 in words is "twenty-one million, nine hundred ninety-four thousand, eight hundred forty-nine".