12521905 has 8 divisors (see below), whose sum is σ = 16392384. Its totient is φ = 9106800.

The previous prime is 12521903. The next prime is 12521921. The reversal of 12521905 is 50912521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12521905 - 2¹ = 12521903 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12521905.

It is not an unprimeable number, because it can be changed into a prime (12521903) 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 7 ways as a sum of consecutive naturals, for example, 113781 + ... + 113890.

It is an arithmetic number, because the mean of its divisors is an integer number (2049048).

Almost surely, 2^12521905 is an apocalyptic number.

It is an amenable number.

12521905 is a deficient number, since it is larger than the sum of its proper divisors (3870479).

12521905 is a wasteful number, since it uses less digits than its factorization.

12521905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227687.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 12521905 is about 3538.6303847675. The cubic root of 12521905 is about 232.2149279073.

The spelling of 12521905 in words is "twelve million, five hundred twenty-one thousand, nine hundred five".