21944994213 has 4 divisors (see below), whose sum is σ = 29259992288. Its totient is φ = 14629996140.

The previous prime is 21944994199. The next prime is 21944994251. The reversal of 21944994213 is 31249944912.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21944994213 - 2²⁶ = 21877885349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21944994293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3657499033 + ... + 3657499038.

It is an arithmetic number, because the mean of its divisors is an integer number (7314998072).

Almost surely, 2^21944994213 is an apocalyptic number.

It is an amenable number.

21944994213 is a deficient number, since it is larger than the sum of its proper divisors (7314998075).

21944994213 is an equidigital number, since it uses as much as digits as its factorization.

21944994213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7314998074.

The product of its digits is 559872, while the sum is 48.

The spelling of 21944994213 in words is "twenty-one billion, nine hundred forty-four million, nine hundred ninety-four thousand, two hundred thirteen".