1211011100 has 72 divisors (see below), whose sum is σ = 2841380640. Its totient is φ = 445351680.

The previous prime is 1211011097. The next prime is 1211011121. The reversal of 1211011100 is 11101121.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 347969 + ... + 351431.

It is an arithmetic number, because the mean of its divisors is an integer number (39463620).

Almost surely, 2^1211011100 is an apocalyptic number.

1211011100 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 1211011100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1420690320).

1211011100 is an abundant number, since it is smaller than the sum of its proper divisors (1630369540).

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

1211011100 is a wasteful number, since it uses less digits than its factorization.

1211011100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3759 (or 3752 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 8.

The square root of 1211011100 is about 34799.5847676377. The cubic root of 1211011100 is about 1065.8989669191.

Adding to 1211011100 its reverse (11101121), we get a palindrome (1222112221).

The spelling of 1211011100 in words is "one billion, two hundred eleven million, eleven thousand, one hundred".