21309381367 has 2 divisors, whose sum is σ = 21309381368. Its totient is φ = 21309381366.

The previous prime is 21309381349. The next prime is 21309381413. The reversal of 21309381367 is 76318390312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21309381367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21309381967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10654690683 + 10654690684.

It is an arithmetic number, because the mean of its divisors is an integer number (10654690684).

Almost surely, 2^21309381367 is an apocalyptic number.

21309381367 is a deficient number, since it is larger than the sum of its proper divisors (1).

21309381367 is an equidigital number, since it uses as much as digits as its factorization.

21309381367 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 43.

The spelling of 21309381367 in words is "twenty-one billion, three hundred nine million, three hundred eighty-one thousand, three hundred sixty-seven".