11721210533491 has 2 divisors, whose sum is σ = 11721210533492. Its totient is φ = 11721210533490.

The previous prime is 11721210533489. The next prime is 11721210533521. The reversal of 11721210533491 is 19433501212711.

11721210533491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (19433501212711) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11721210533491 - 2¹ = 11721210533489 is a prime.

Together with 11721210533489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (11721210533471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5860605266745 + 5860605266746.

It is an arithmetic number, because the mean of its divisors is an integer number (5860605266746).

Almost surely, 2^{11721210533491} is an apocalyptic number.

11721210533491 is a deficient number, since it is larger than the sum of its proper divisors (1).

11721210533491 is an equidigital number, since it uses as much as digits as its factorization.

11721210533491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 40.

The spelling of 11721210533491 in words is "eleven trillion, seven hundred twenty-one billion, two hundred ten million, five hundred thirty-three thousand, four hundred ninety-one".