13530420521 has 4 divisors (see below), whose sum is σ = 13580348544. Its totient is φ = 13480492500.

The previous prime is 13530420493. The next prime is 13530420523. The reversal of 13530420521 is 12502403531.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13530420521 is a prime.

It is a super-2 number, since 2×13530420521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13530420523) 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, 24963605 + ... + 24964146.

It is an arithmetic number, because the mean of its divisors is an integer number (3395087136).

Almost surely, 2^13530420521 is an apocalyptic number.

It is an amenable number.

13530420521 is a deficient number, since it is larger than the sum of its proper divisors (49928023).

13530420521 is an equidigital number, since it uses as much as digits as its factorization.

13530420521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49928022.

The product of its (nonzero) digits is 3600, while the sum is 26.

The spelling of 13530420521 in words is "thirteen billion, five hundred thirty million, four hundred twenty thousand, five hundred twenty-one".