1221313513 has 16 divisors (see below), whose sum is σ = 1432765440. Its totient is φ = 1019448000.

The previous prime is 1221313493. The next prime is 1221313553. The reversal of 1221313513 is 3153131221.

It is a cyclic number.

It is not a de Polignac number, because 1221313513 - 2⁵ = 1221313481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221313553) 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, 28968 + ... + 57286.

It is an arithmetic number, because the mean of its divisors is an integer number (89547840).

Almost surely, 2^1221313513 is an apocalyptic number.

It is an amenable number.

1221313513 is a deficient number, since it is larger than the sum of its proper divisors (211451927).

1221313513 is a wasteful number, since it uses less digits than its factorization.

1221313513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28488.

The product of its digits is 540, while the sum is 22.

The square root of 1221313513 is about 34947.2962187349. The cubic root of 1221313513 is about 1068.9130701188.

Adding to 1221313513 its reverse (3153131221), we get a palindrome (4374444734).

The spelling of 1221313513 in words is "one billion, two hundred twenty-one million, three hundred thirteen thousand, five hundred thirteen".