1221320113 has 32 divisors (see below), whose sum is σ = 1387366400. Its totient is φ = 1067489280.

The previous prime is 1221320083. The next prime is 1221320141. The reversal of 1221320113 is 3110231221.

It is not a de Polignac number, because 1221320113 - 2¹³ = 1221311921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221320143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6137188 + ... + 6137386.

It is an arithmetic number, because the mean of its divisors is an integer number (43355200).

Almost surely, 2^1221320113 is an apocalyptic number.

1221320113 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1221320113 is a deficient number, since it is larger than the sum of its proper divisors (166046287).

1221320113 is a wasteful number, since it uses less digits than its factorization.

1221320113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1221320113 is about 34947.3906465132. The cubic root of 1221320113 is about 1068.9149955904.

Adding to 1221320113 its reverse (3110231221), we get a palindrome (4331551334).

The spelling of 1221320113 in words is "one billion, two hundred twenty-one million, three hundred twenty thousand, one hundred thirteen".