1313221643 has 4 divisors (see below), whose sum is σ = 1313373600. Its totient is φ = 1313069688.

The previous prime is 1313221631. The next prime is 1313221687. The reversal of 1313221643 is 3461223131.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1313221643 - 2¹⁰ = 1313220619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1373221643) 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 3 ways as a sum of consecutive naturals, for example, 62180 + ... + 80577.

It is an arithmetic number, because the mean of its divisors is an integer number (328343400).

Almost surely, 2^1313221643 is an apocalyptic number.

1313221643 is a deficient number, since it is larger than the sum of its proper divisors (151957).

1313221643 is an equidigital number, since it uses as much as digits as its factorization.

1313221643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151956.

The product of its digits is 2592, while the sum is 26.

The square root of 1313221643 is about 36238.4001164511. The cubic root of 1313221643 is about 1095.0804116563.

Adding to 1313221643 its reverse (3461223131), we get a palindrome (4774444774).

The spelling of 1313221643 in words is "one billion, three hundred thirteen million, two hundred twenty-one thousand, six hundred forty-three".