1221100113 has 16 divisors (see below), whose sum is σ = 1715763200. Its totient is φ = 770348880.

The previous prime is 1221100063. The next prime is 1221100121. The reversal of 1221100113 is 3110011221.

It is not a de Polignac number, because 1221100113 - 2¹⁴ = 1221083729 is a prime.

It is a super-2 number, since 2×1221100113² = 2982170971937225538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221100193) 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, 40728 + ... + 64038.

It is an arithmetic number, because the mean of its divisors is an integer number (107235200).

Almost surely, 2^1221100113 is an apocalyptic number.

It is an amenable number.

1221100113 is a deficient number, since it is larger than the sum of its proper divisors (494663087).

1221100113 is a wasteful number, since it uses less digits than its factorization.

1221100113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24252.

The product of its (nonzero) digits is 12, while the sum is 12.

The square root of 1221100113 is about 34944.2429163947. The cubic root of 1221100113 is about 1068.8508094642.

Adding to 1221100113 its reverse (3110011221), we get a palindrome (4331111334).

The spelling of 1221100113 in words is "one billion, two hundred twenty-one million, one hundred thousand, one hundred thirteen".