12219561 has 6 divisors (see below), whose sum is σ = 17650490. Its totient is φ = 8146368.

The previous prime is 12219551. The next prime is 12219587. The reversal of 12219561 is 16591221.

It can be written as a sum of positive squares in only one way, i.e., 11943936 + 275625 = 3456^2 + 525^2 .

It is not a de Polignac number, because 12219561 - 2⁶ = 12219497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12219511) 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 5 ways as a sum of consecutive naturals, for example, 678856 + ... + 678873.

Almost surely, 2^12219561 is an apocalyptic number.

It is an amenable number.

12219561 is a deficient number, since it is larger than the sum of its proper divisors (5430929).

12219561 is a wasteful number, since it uses less digits than its factorization.

12219561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1357735 (or 1357732 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 12219561 is about 3495.6488668057. The cubic root of 12219561 is about 230.3307214488.

It can be divided in two parts, 122 and 19561, that added together give a 9-th power (19683 = 3⁹).

The spelling of 12219561 in words is "twelve million, two hundred nineteen thousand, five hundred sixty-one".