1211011111992 has 128 divisors (see below), whose sum is σ = 3395950272000. Its totient is φ = 356745392640.

The previous prime is 1211011111991. The next prime is 1211011112023. The reversal of 1211011111992 is 2991111101121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211011111991) 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, 1128109 + ... + 1922147.

It is an arithmetic number, because the mean of its divisors is an integer number (26530861500).

Almost surely, 2^{1211011111992} is an apocalyptic number.

1211011111992 is a gapful number since it is divisible by the number (12) 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 1211011111992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1697975136000).

1211011111992 is an abundant number, since it is smaller than the sum of its proper divisors (2184939160008).

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

1211011111992 is a wasteful number, since it uses less digits than its factorization.

1211011111992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794221 (or 794217 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 30.

The spelling of 1211011111992 in words is "one trillion, two hundred eleven billion, eleven million, one hundred eleven thousand, nine hundred ninety-two".