21344311091 has 2 divisors, whose sum is σ = 21344311092. Its totient is φ = 21344311090.

The previous prime is 21344311057. The next prime is 21344311111. The reversal of 21344311091 is 19011344312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21344311091 is a prime.

It is a super-2 number, since 2×21344311091² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21344311691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672155545 + 10672155546.

It is an arithmetic number, because the mean of its divisors is an integer number (10672155546).

Almost surely, 2^21344311091 is an apocalyptic number.

21344311091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21344311091 is an equidigital number, since it uses as much as digits as its factorization.

21344311091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 29.

The spelling of 21344311091 in words is "twenty-one billion, three hundred forty-four million, three hundred eleven thousand, ninety-one".