21340013643 has 12 divisors (see below), whose sum is σ = 33195576960. Its totient is φ = 13132316016.

The previous prime is 21340013579. The next prime is 21340013707. The reversal of 21340013643 is 34631004312.

21340013643 is a `hidden beast` number, since 2 + 1 + 3 + 4 + 0 + 0 + 13 + 643 = 666.

It is an interprime number because it is at equal distance from previous prime (21340013579) and next prime (21340013707).

It is not a de Polignac number, because 21340013643 - 2⁶ = 21340013579 is a prime.

It is a super-2 number, since 2×21340013643² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21340013743) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 91196523 + ... + 91196756.

It is an arithmetic number, because the mean of its divisors is an integer number (2766298080).

Almost surely, 2^21340013643 is an apocalyptic number.

21340013643 is a deficient number, since it is larger than the sum of its proper divisors (11855563317).

21340013643 is a wasteful number, since it uses less digits than its factorization.

21340013643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182393298 (or 182393295 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

Adding to 21340013643 its reverse (34631004312), we get a palindrome (55971017955).

The spelling of 21340013643 in words is "twenty-one billion, three hundred forty million, thirteen thousand, six hundred forty-three".