1211100012120 has 128 divisors (see below), whose sum is σ = 3735623865600. Its totient is φ = 313883859456.

The previous prime is 1211100012097. The next prime is 1211100012121. The reversal of 1211100012120 is 212100011121.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1211100012096 and 1211100012105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211100012121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3876711 + ... + 4177449.

It is an arithmetic number, because the mean of its divisors is an integer number (29184561450).

Almost surely, 2^{1211100012120} is an apocalyptic number.

1211100012120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211100012120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1867811932800).

1211100012120 is an abundant number, since it is smaller than the sum of its proper divisors (2524523853480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211100012120 is a wasteful number, since it uses less digits than its factorization.

1211100012120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301697 (or 301693 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1211100012120 its reverse (212100011121), we get a palindrome (1423200023241).

Subtracting from 1211100012120 its reverse (212100011121), we obtain a palindrome (999000000999).

The spelling of 1211100012120 in words is "one trillion, two hundred eleven billion, one hundred million, twelve thousand, one hundred twenty".