1219781321121 has 16 divisors (see below), whose sum is σ = 1822179469248. Its totient is φ = 719281368000.

The previous prime is 1219781321111. The next prime is 1219781321137. The reversal of 1219781321121 is 1211231879121.

It is not a de Polignac number, because 1219781321121 - 2¹⁵ = 1219781288353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1219781321121.

It is not an unprimeable number, because it can be changed into a prime (1219781321111) 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, 499499730 + ... + 499502171.

It is an arithmetic number, because the mean of its divisors is an integer number (113886216828).

Almost surely, 2^{1219781321121} is an apocalyptic number.

1219781321121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1219781321121 is a deficient number, since it is larger than the sum of its proper divisors (602398148127).

1219781321121 is a wasteful number, since it uses less digits than its factorization.

1219781321121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999001952.

The product of its digits is 12096, while the sum is 39.

It can be divided in two parts, 12197 and 81321121, that added together give a palindrome (81333318).

The spelling of 1219781321121 in words is "one trillion, two hundred nineteen billion, seven hundred eighty-one million, three hundred twenty-one thousand, one hundred twenty-one".