12215861 has 8 divisors (see below), whose sum is σ = 13990080. Its totient is φ = 10448928.

The previous prime is 12215851. The next prime is 12215897. The reversal of 12215861 is 16851221.

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

It is a de Polignac number, because none of the positive numbers 2^k-12215861 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 12215861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12215821) 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, 2450 + ... + 5516.

It is an arithmetic number, because the mean of its divisors is an integer number (1748760).

Almost surely, 2^12215861 is an apocalyptic number.

It is an amenable number.

12215861 is a deficient number, since it is larger than the sum of its proper divisors (1774219).

12215861 is an equidigital number, since it uses as much as digits as its factorization.

12215861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3643.

The product of its digits is 960, while the sum is 26.

The square root of 12215861 is about 3495.1195973815. The cubic root of 12215861 is about 230.3074715764.

The spelling of 12215861 in words is "twelve million, two hundred fifteen thousand, eight hundred sixty-one".