12217581 has 16 divisors (see below), whose sum is σ = 18273600. Its totient is φ = 8067024.

The previous prime is 12217573. The next prime is 12217591. The reversal of 12217581 is 18571221.

12217581 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12217581 - 2³ = 12217573 is a prime.

It is a super-2 number, since 2×12217581² = 298538570983122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12217591) 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, 775 + ... + 5003.

It is an arithmetic number, because the mean of its divisors is an integer number (1142100).

Almost surely, 2^12217581 is an apocalyptic number.

It is an amenable number.

12217581 is a deficient number, since it is larger than the sum of its proper divisors (6056019).

12217581 is a wasteful number, since it uses less digits than its factorization.

12217581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4345 (or 4339 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 12217581 is about 3495.3656461091. The cubic root of 12217581 is about 230.3182802091.

The spelling of 12217581 in words is "twelve million, two hundred seventeen thousand, five hundred eighty-one".