12521917 has 4 divisors (see below), whose sum is σ = 12544956. Its totient is φ = 12498880.

The previous prime is 12521903. The next prime is 12521921. The reversal of 12521917 is 71912521.

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 763876 + 11758041 = 874^2 + 3429^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12521917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12521017) 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, 10684 + ... + 11797.

It is an arithmetic number, because the mean of its divisors is an integer number (3136239).

Almost surely, 2^12521917 is an apocalyptic number.

It is an amenable number.

12521917 is a deficient number, since it is larger than the sum of its proper divisors (23039).

12521917 is an equidigital number, since it uses as much as digits as its factorization.

12521917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23038.

The product of its digits is 1260, while the sum is 28.

The square root of 12521917 is about 3538.6320803384. The cubic root of 12521917 is about 232.2150020860.

The spelling of 12521917 in words is "twelve million, five hundred twenty-one thousand, nine hundred seventeen".