21994319 has 2 divisors, whose sum is σ = 21994320. Its totient is φ = 21994318.

The previous prime is 21994237. The next prime is 21994321. The reversal of 21994319 is 91349912.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21994319 is a prime.

It is a super-2 number, since 2×21994319² = 967500136547522, which contains 22 as substring.

Together with 21994321, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21994369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10997159 + 10997160.

It is an arithmetic number, because the mean of its divisors is an integer number (10997160).

Almost surely, 2^21994319 is an apocalyptic number.

21994319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21994319 is an equidigital number, since it uses as much as digits as its factorization.

21994319 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17496, while the sum is 38.

The square root of 21994319 is about 4689.8101240882. The cubic root of 21994319 is about 280.1798122234.

The spelling of 21994319 in words is "twenty-one million, nine hundred ninety-four thousand, three hundred nineteen".