21091714393 has 2 divisors, whose sum is σ = 21091714394. Its totient is φ = 21091714392.

The previous prime is 21091714387. The next prime is 21091714421. The reversal of 21091714393 is 39341719012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16116810304 + 4974904089 = 126952^2 + 70533^2 .

It is a cyclic number.

It is not a de Polignac number, because 21091714393 - 2⁵ = 21091714361 is a prime.

It is not a weakly prime, because it can be changed into another prime (21091714333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10545857196 + 10545857197.

It is an arithmetic number, because the mean of its divisors is an integer number (10545857197).

Almost surely, 2^21091714393 is an apocalyptic number.

It is an amenable number.

21091714393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21091714393 is an equidigital number, since it uses as much as digits as its factorization.

21091714393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40824, while the sum is 40.

The spelling of 21091714393 in words is "twenty-one billion, ninety-one million, seven hundred fourteen thousand, three hundred ninety-three".