1313121221 has 8 divisors (see below), whose sum is σ = 1372441920. Its totient is φ = 1253986272.

The previous prime is 1313121193. The next prime is 1313121253. The reversal of 1313121221 is 1221213131.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1313121221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1313121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1313121721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31880 + ... + 60353.

It is an arithmetic number, because the mean of its divisors is an integer number (171555240).

Almost surely, 2^1313121221 is an apocalyptic number.

It is an amenable number.

1313121221 is a deficient number, since it is larger than the sum of its proper divisors (59320699).

1313121221 is an equidigital number, since it uses as much as digits as its factorization.

1313121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92875.

The product of its digits is 72, while the sum is 17.

The square root of 1313121221 is about 36237.0145155475. The cubic root of 1313121221 is about 1095.0524973615.

Adding to 1313121221 its reverse (1221213131), we get a palindrome (2534334352).

The spelling of 1313121221 in words is "one billion, three hundred thirteen million, one hundred twenty-one thousand, two hundred twenty-one".