1221431313 has 8 divisors (see below), whose sum is σ = 1632204000. Its totient is φ = 812473088.

The previous prime is 1221431291. The next prime is 1221431327. The reversal of 1221431313 is 3131341221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221431313 - 2¹⁰ = 1221430289 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221431313.

It is not an unprimeable number, because it can be changed into a prime (1221431213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 452043 + ... + 454736.

It is an arithmetic number, because the mean of its divisors is an integer number (204025500).

Almost surely, 2^1221431313 is an apocalyptic number.

It is an amenable number.

1221431313 is a deficient number, since it is larger than the sum of its proper divisors (410772687).

1221431313 is an equidigital number, since it uses as much as digits as its factorization.

1221431313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907231.

The product of its digits is 432, while the sum is 21.

The square root of 1221431313 is about 34948.9815731446. The cubic root of 1221431313 is about 1068.9474358270.

Adding to 1221431313 its reverse (3131341221), we get a palindrome (4352772534).

The spelling of 1221431313 in words is "one billion, two hundred twenty-one million, four hundred thirty-one thousand, three hundred thirteen".