12687521 has 12 divisors (see below), whose sum is σ = 16101360. Its totient is φ = 9885960.

The previous prime is 12687469. The next prime is 12687523. The reversal of 12687521 is 12578621.

It is a de Polignac number, because none of the positive numbers 2^k-12687521 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12687523) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11231 + ... + 12308.

It is an arithmetic number, because the mean of its divisors is an integer number (1341780).

Almost surely, 2^12687521 is an apocalyptic number.

12687521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12687521 is a deficient number, since it is larger than the sum of its proper divisors (3413839).

12687521 is a wasteful number, since it uses less digits than its factorization.

12687521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23564 (or 23557 counting only the distinct ones).

The product of its digits is 6720, while the sum is 32.

The square root of 12687521 is about 3561.9546600146. The cubic root of 12687521 is about 233.2342134554.

Subtracting from 12687521 its reverse (12578621), we obtain a square (108900 = 330²).

The spelling of 12687521 in words is "twelve million, six hundred eighty-seven thousand, five hundred twenty-one".