21340220513 has 4 divisors (see below), whose sum is σ = 22595527620. Its totient is φ = 20084913408.

The previous prime is 21340220477. The next prime is 21340220537. The reversal of 21340220513 is 31502204312.

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 9127318369 + 12212902144 = 95537^2 + 110512^2 .

It is a cyclic number.

It is not a de Polignac number, because 21340220513 - 2¹⁰ = 21340219489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21340220543) 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, 627653528 + ... + 627653561.

It is an arithmetic number, because the mean of its divisors is an integer number (5648881905).

Almost surely, 2^21340220513 is an apocalyptic number.

It is an amenable number.

21340220513 is a deficient number, since it is larger than the sum of its proper divisors (1255307107).

21340220513 is a wasteful number, since it uses less digits than its factorization.

21340220513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255307106.

The product of its (nonzero) digits is 1440, while the sum is 23.

Adding to 21340220513 its reverse (31502204312), we get a palindrome (52842424825).

The spelling of 21340220513 in words is "twenty-one billion, three hundred forty million, two hundred twenty thousand, five hundred thirteen".