1211111080 has 96 divisors (see below), whose sum is σ = 2832710400. Its totient is φ = 465903360.

The previous prime is 1211111063. The next prime is 1211111081. The reversal of 1211111080 is 801111121.

It is not an unprimeable number, because it can be changed into a prime (1211111081) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11758309 + ... + 11758411.

It is an arithmetic number, because the mean of its divisors is an integer number (29507400).

Almost surely, 2^1211111080 is an apocalyptic number.

1211111080 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 1211111080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1416355200).

1211111080 is an abundant number, since it is smaller than the sum of its proper divisors (1621599320).

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

1211111080 is a wasteful number, since it uses less digits than its factorization.

1211111080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 16.

The square root of 1211111080 is about 34801.0212493829. The cubic root of 1211111080 is about 1065.9282993356.

The spelling of 1211111080 in words is "one billion, two hundred eleven million, one hundred eleven thousand, eighty".