12281521 has 8 divisors (see below), whose sum is σ = 14415680. Its totient is φ = 10242288.

The previous prime is 12281519. The next prime is 12281539. The reversal of 12281521 is 12518221.

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

It is not a de Polignac number, because 12281521 - 2¹ = 12281519 is a prime.

It is the 3505-th Hogben number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12281492 and 12281501.

It is not an unprimeable number, because it can be changed into a prime (12281221) by changing a digit.

It is a nontrivial repunit in base 3504.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23451 + ... + 23968.

It is an arithmetic number, because the mean of its divisors is an integer number (1801960).

Almost surely, 2^12281521 is an apocalyptic number.

It is an amenable number.

12281521 is a deficient number, since it is larger than the sum of its proper divisors (2134159).

12281521 is an equidigital number, since it uses as much as digits as its factorization.

12281521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47463.

The product of its digits is 320, while the sum is 22.

The square root of 12281521 is about 3504.5001070053. The cubic root of 12281521 is about 230.7193671096.

Adding to 12281521 its reverse (12518221), we get a palindrome (24799742).

The spelling of 12281521 in words is "twelve million, two hundred eighty-one thousand, five hundred twenty-one".