21344410091 has 2 divisors, whose sum is σ = 21344410092. Its totient is φ = 21344410090.

The previous prime is 21344410079. The next prime is 21344410123. The reversal of 21344410091 is 19001444312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21344410091 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21344410051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672205045 + 10672205046.

It is an arithmetic number, because the mean of its divisors is an integer number (10672205046).

Almost surely, 2^21344410091 is an apocalyptic number.

21344410091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21344410091 is an equidigital number, since it uses as much as digits as its factorization.

21344410091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 29.

The spelling of 21344410091 in words is "twenty-one billion, three hundred forty-four million, four hundred ten thousand, ninety-one".