21346135643 has 4 divisors (see below), whose sum is σ = 24395583600. Its totient is φ = 18296687688.

The previous prime is 21346135621. The next prime is 21346135649. The reversal of 21346135643 is 34653164312.

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 21346135643 - 2³⁴ = 4166266459 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21346135597 and 21346135606.

It is not an unprimeable number, because it can be changed into a prime (21346135649) 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, 1524723968 + ... + 1524723981.

It is an arithmetic number, because the mean of its divisors is an integer number (6098895900).

Almost surely, 2^21346135643 is an apocalyptic number.

21346135643 is a deficient number, since it is larger than the sum of its proper divisors (3049447957).

21346135643 is an equidigital number, since it uses as much as digits as its factorization.

21346135643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3049447956.

The product of its digits is 155520, while the sum is 38.

Adding to 21346135643 its reverse (34653164312), we get a palindrome (55999299955).

The spelling of 21346135643 in words is "twenty-one billion, three hundred forty-six million, one hundred thirty-five thousand, six hundred forty-three".