13453533521 has 4 divisors (see below), whose sum is σ = 13917448500. Its totient is φ = 12989618544.

The previous prime is 13453533503. The next prime is 13453533523. The reversal of 13453533521 is 12533535431.

It is a happy number.

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 10193123521 + 3260410000 = 100961^2 + 57100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13453533521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13453533523) 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, 231957446 + ... + 231957503.

It is an arithmetic number, because the mean of its divisors is an integer number (3479362125).

Almost surely, 2^13453533521 is an apocalyptic number.

It is an amenable number.

13453533521 is a deficient number, since it is larger than the sum of its proper divisors (463914979).

13453533521 is an equidigital number, since it uses as much as digits as its factorization.

13453533521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463914978.

The product of its digits is 81000, while the sum is 35.

The spelling of 13453533521 in words is "thirteen billion, four hundred fifty-three million, five hundred thirty-three thousand, five hundred twenty-one".