12381521 has 16 divisors (see below), whose sum is σ = 14083200. Its totient is φ = 10821888.

The previous prime is 12381517. The next prime is 12381557. The reversal of 12381521 is 12518321.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 12381521 - 2² = 12381517 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12381511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12185 + ... + 13161.

It is an arithmetic number, because the mean of its divisors is an integer number (880200).

Almost surely, 2^12381521 is an apocalyptic number.

It is an amenable number.

12381521 is a deficient number, since it is larger than the sum of its proper divisors (1701679).

12381521 is a wasteful number, since it uses less digits than its factorization.

12381521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048.

The product of its digits is 480, while the sum is 23.

The square root of 12381521 is about 3518.7385523792. The cubic root of 12381521 is about 231.3438717019.

Adding to 12381521 its reverse (12518321), we get a palindrome (24899842).

The spelling of 12381521 in words is "twelve million, three hundred eighty-one thousand, five hundred twenty-one".