12181521 has 8 divisors (see below), whose sum is σ = 17718624. Its totient is φ = 7382720.

The previous prime is 12181493. The next prime is 12181523. The reversal of 12181521 is 12518121.

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

It is a cyclic number.

It is not a de Polignac number, because 12181521 - 2⁶ = 12181457 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12181523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 184536 + ... + 184601.

It is an arithmetic number, because the mean of its divisors is an integer number (2214828).

Almost surely, 2^12181521 is an apocalyptic number.

12181521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12181521 is a deficient number, since it is larger than the sum of its proper divisors (5537103).

12181521 is a wasteful number, since it uses less digits than its factorization.

12181521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369151.

The product of its digits is 160, while the sum is 21.

The square root of 12181521 is about 3490.2035757245. The cubic root of 12181521 is about 230.0914633082.

Adding to 12181521 its reverse (12518121), we get a palindrome (24699642).

The spelling of 12181521 in words is "twelve million, one hundred eighty-one thousand, five hundred twenty-one".