12213945 has 24 divisors (see below), whose sum is σ = 21270600. Its totient is φ = 6483456.

The previous prime is 12213931. The next prime is 12213947. The reversal of 12213945 is 54931221.

It can be written as a sum of positive squares in 4 ways, for example, as 19881 + 12194064 = 141^2 + 3492^2 .

It is not a de Polignac number, because 12213945 - 2⁵ = 12213913 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12213947) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11601 + ... + 12609.

It is an arithmetic number, because the mean of its divisors is an integer number (886275).

Almost surely, 2^12213945 is an apocalyptic number.

12213945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12213945 is a deficient number, since it is larger than the sum of its proper divisors (9056655).

12213945 is a wasteful number, since it uses less digits than its factorization.

12213945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1289 (or 1286 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 12213945 is about 3494.8454901469. The cubic root of 12213945 is about 230.2954300678.

The spelling of 12213945 in words is "twelve million, two hundred thirteen thousand, nine hundred forty-five".