12520211521 has 12 divisors (see below), whose sum is σ = 12975639040. Its totient is φ = 12068196840.

The previous prime is 12520211507. The next prime is 12520211549. The reversal of 12520211521 is 12511202521.

It is a happy number.

It is not a de Polignac number, because 12520211521 - 2⁵ = 12520211489 is a prime.

It is a super-2 number, since 2×12520211521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12520211492 and 12520211501.

It is not an unprimeable number, because it can be changed into a prime (12520212521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2141320 + ... + 2147158.

Almost surely, 2^12520211521 is an apocalyptic number.

It is an amenable number.

12520211521 is a deficient number, since it is larger than the sum of its proper divisors (455427519).

12520211521 is an frugal number, since it uses more digits than its factorization.

12520211521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6396 (or 6133 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 22.

The spelling of 12520211521 in words is "twelve billion, five hundred twenty million, two hundred eleven thousand, five hundred twenty-one".