21513534525113 has 4 divisors (see below), whose sum is σ = 22779036556020. Its totient is φ = 20248032494208.

The previous prime is 21513534525101. The next prime is 21513534525139. The reversal of 21513534525113 is 31152543531512.

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 13820943828409 + 7692590696704 = 3717653^2 + 2773552^2 .

It is a cyclic number.

It is not a de Polignac number, because 21513534525113 - 2²⁸ = 21513266089657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21513534525163) 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, 632751015428 + ... + 632751015461.

It is an arithmetic number, because the mean of its divisors is an integer number (5694759139005).

Almost surely, 2^{21513534525113} is an apocalyptic number.

It is an amenable number.

21513534525113 is a deficient number, since it is larger than the sum of its proper divisors (1265502030907).

21513534525113 is a wasteful number, since it uses less digits than its factorization.

21513534525113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1265502030906.

The product of its digits is 270000, while the sum is 41.

The spelling of 21513534525113 in words is "twenty-one trillion, five hundred thirteen billion, five hundred thirty-four million, five hundred twenty-five thousand, one hundred thirteen".