21064343361 has 4 divisors (see below), whose sum is σ = 28085791152. Its totient is φ = 14042895572.

The previous prime is 21064343359. The next prime is 21064343381. The reversal of 21064343361 is 16334346012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21064343361 - 2¹ = 21064343359 is a prime.

It is a super-2 number, since 2×21064343361² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21064343351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3510723891 + ... + 3510723896.

It is an arithmetic number, because the mean of its divisors is an integer number (7021447788).

Almost surely, 2^21064343361 is an apocalyptic number.

It is an amenable number.

21064343361 is a deficient number, since it is larger than the sum of its proper divisors (7021447791).

21064343361 is an equidigital number, since it uses as much as digits as its factorization.

21064343361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7021447790.

The product of its (nonzero) digits is 31104, while the sum is 33.

Adding to 21064343361 its reverse (16334346012), we get a palindrome (37398689373).

The spelling of 21064343361 in words is "twenty-one billion, sixty-four million, three hundred forty-three thousand, three hundred sixty-one".