1221344313 has 16 divisors (see below), whose sum is σ = 1872245760. Its totient is φ = 693729936.

The previous prime is 1221344287. The next prime is 1221344381. The reversal of 1221344313 is 3134431221.

It is a happy number.

It is not a de Polignac number, because 1221344313 - 2¹² = 1221340217 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1221344393) 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, 170623 + ... + 177636.

It is an arithmetic number, because the mean of its divisors is an integer number (117015360).

Almost surely, 2^1221344313 is an apocalyptic number.

It is an amenable number.

1221344313 is a deficient number, since it is larger than the sum of its proper divisors (650901447).

1221344313 is a wasteful number, since it uses less digits than its factorization.

1221344313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348436.

The product of its digits is 1728, while the sum is 24.

The square root of 1221344313 is about 34947.7368795177. The cubic root of 1221344313 is about 1068.9220555937.

Adding to 1221344313 its reverse (3134431221), we get a palindrome (4355775534).

The spelling of 1221344313 in words is "one billion, two hundred twenty-one million, three hundred forty-four thousand, three hundred thirteen".