21513269643 has 4 divisors (see below), whose sum is σ = 28684359528. Its totient is φ = 14342179760.

The previous prime is 21513269623. The next prime is 21513269647. The reversal of 21513269643 is 34696231512.

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

It is a cyclic number.

It is not a de Polignac number, because 21513269643 - 2⁸ = 21513269387 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21513269595 and 21513269604.

It is not an unprimeable number, because it can be changed into a prime (21513269647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3585544938 + ... + 3585544943.

It is an arithmetic number, because the mean of its divisors is an integer number (7171089882).

Almost surely, 2^21513269643 is an apocalyptic number.

21513269643 is a deficient number, since it is larger than the sum of its proper divisors (7171089885).

21513269643 is an equidigital number, since it uses as much as digits as its factorization.

21513269643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7171089884.

The product of its digits is 233280, while the sum is 42.

The spelling of 21513269643 in words is "twenty-one billion, five hundred thirteen million, two hundred sixty-nine thousand, six hundred forty-three".