12645521 has 4 divisors (see below), whose sum is σ = 14452032. Its totient is φ = 10839012.

The previous prime is 12645509. The next prime is 12645533. The reversal of 12645521 is 12554621.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12554621 = 191 ⋅65731.

It is an interprime number because it is at equal distance from previous prime (12645509) and next prime (12645533).

It is a cyclic number.

It is not a de Polignac number, because 12645521 - 2²² = 8451217 is a prime.

It is a super-2 number, since 2×12645521² = 319818402722882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12645821) 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, 903245 + ... + 903258.

It is an arithmetic number, because the mean of its divisors is an integer number (3613008).

Almost surely, 2^12645521 is an apocalyptic number.

It is an amenable number.

12645521 is a deficient number, since it is larger than the sum of its proper divisors (1806511).

12645521 is an equidigital number, since it uses as much as digits as its factorization.

12645521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1806510.

The product of its digits is 2400, while the sum is 26.

The square root of 12645521 is about 3556.0541334462. The cubic root of 12645521 is about 232.9765674827.

The spelling of 12645521 in words is "twelve million, six hundred forty-five thousand, five hundred twenty-one".