21264446191 has 2 divisors, whose sum is σ = 21264446192. Its totient is φ = 21264446190.

The previous prime is 21264446167. The next prime is 21264446233. The reversal of 21264446191 is 19164446212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21264446191 - 2⁹ = 21264445679 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21264444191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10632223095 + 10632223096.

It is an arithmetic number, because the mean of its divisors is an integer number (10632223096).

Almost surely, 2^21264446191 is an apocalyptic number.

21264446191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21264446191 is an equidigital number, since it uses as much as digits as its factorization.

21264446191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 40.

The spelling of 21264446191 in words is "twenty-one billion, two hundred sixty-four million, four hundred forty-six thousand, one hundred ninety-one".