21005305367 has 2 divisors, whose sum is σ = 21005305368. Its totient is φ = 21005305366.

The previous prime is 21005305351. The next prime is 21005305369. The reversal of 21005305367 is 76350350012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21005305367 - 2⁴ = 21005305351 is a prime.

Together with 21005305369, 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 (21005305369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502652683 + 10502652684.

It is an arithmetic number, because the mean of its divisors is an integer number (10502652684).

Almost surely, 2^21005305367 is an apocalyptic number.

21005305367 is a deficient number, since it is larger than the sum of its proper divisors (1).

21005305367 is an equidigital number, since it uses as much as digits as its factorization.

21005305367 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18900, while the sum is 32.

Adding to 21005305367 its reverse (76350350012), we get a palindrome (97355655379).

The spelling of 21005305367 in words is "twenty-one billion, five million, three hundred five thousand, three hundred sixty-seven".