21994849889 has 2 divisors, whose sum is σ = 21994849890. Its totient is φ = 21994849888.

The previous prime is 21994849867. The next prime is 21994849913. The reversal of 21994849889 is 98894849912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21164430400 + 830419489 = 145480^2 + 28817^2 .

It is a cyclic number.

It is not a de Polignac number, because 21994849889 - 2¹⁶ = 21994784353 is a prime.

It is not a weakly prime, because it can be changed into another prime (21994849819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10997424944 + 10997424945.

It is an arithmetic number, because the mean of its divisors is an integer number (10997424945).

Almost surely, 2^21994849889 is an apocalyptic number.

It is an amenable number.

21994849889 is a deficient number, since it is larger than the sum of its proper divisors (1).

21994849889 is an equidigital number, since it uses as much as digits as its factorization.

21994849889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 107495424, while the sum is 71.

The spelling of 21994849889 in words is "twenty-one billion, nine hundred ninety-four million, eight hundred forty-nine thousand, eight hundred eighty-nine".