1221113013123 has 4 divisors (see below), whose sum is σ = 1628150684168. Its totient is φ = 814075342080.

The previous prime is 1221113013119. The next prime is 1221113013283. The reversal of 1221113013123 is 3213103111221.

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

It is not a de Polignac number, because 1221113013123 - 2² = 1221113013119 is a prime.

It is a super-2 number, since 2×1221113013123² (a number of 25 digits) contains 22 as substring.

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 1221113013123.

It is not an unprimeable number, because it can be changed into a prime (1221113083123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203518835518 + ... + 203518835523.

It is an arithmetic number, because the mean of its divisors is an integer number (407037671042).

Almost surely, 2^{1221113013123} is an apocalyptic number.

1221113013123 is a deficient number, since it is larger than the sum of its proper divisors (407037671045).

1221113013123 is an equidigital number, since it uses as much as digits as its factorization.

1221113013123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407037671044.

The product of its (nonzero) digits is 216, while the sum is 21.

Adding to 1221113013123 its reverse (3213103111221), we get a palindrome (4434216124344).

The spelling of 1221113013123 in words is "one trillion, two hundred twenty-one billion, one hundred thirteen million, thirteen thousand, one hundred twenty-three".