121111001100 has 216 divisors, whose sum is σ = 406829273760. Its totient is φ = 30056970240.

The previous prime is 121111001071. The next prime is 121111001107. The reversal of 121111001100 is 1100111121.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (121111001107) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 686836 + ... + 844964.

It is an arithmetic number, because the mean of its divisors is an integer number (1883468860).

Almost surely, 2^121111001100 is an apocalyptic number.

121111001100 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 121111001100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (203414636880).

121111001100 is an abundant number, since it is smaller than the sum of its proper divisors (285718272660).

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

121111001100 is a wasteful number, since it uses less digits than its factorization.

121111001100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158209 (or 158199 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

Adding to 121111001100 its reverse (1100111121), we get a palindrome (122211112221).

The spelling of 121111001100 in words is "one hundred twenty-one billion, one hundred eleven million, one thousand, one hundred".