21264446213 has 4 divisors (see below), whose sum is σ = 21264876780. Its totient is φ = 21264015648.

The previous prime is 21264446191. The next prime is 21264446233. The reversal of 21264446213 is 31264446212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8983817089 + 12280629124 = 94783^2 + 110818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21264446213 - 2³⁰ = 20190704389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264446233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129920 + ... + 243737.

It is an arithmetic number, because the mean of its divisors is an integer number (5316219195).

Almost surely, 2^21264446213 is an apocalyptic number.

It is an amenable number.

21264446213 is a deficient number, since it is larger than the sum of its proper divisors (430567).

21264446213 is an equidigital number, since it uses as much as digits as its factorization.

21264446213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430566.

The product of its digits is 55296, while the sum is 35.

Subtracting 21264446213 from its reverse (31264446212), we obtain a palindrome (9999999999).

The spelling of 21264446213 in words is "twenty-one billion, two hundred sixty-four million, four hundred forty-six thousand, two hundred thirteen".