1121220100 has 288 divisors, whose sum is σ = 3415781376. Its totient is φ = 307929600.

The previous prime is 1121220097. The next prime is 1121220101. The reversal of 1121220100 is 10221211.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (1121220101) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2302057 + ... + 2302543.

It is an arithmetic number, because the mean of its divisors is an integer number (11860352).

Almost surely, 2^1121220100 is an apocalyptic number.

1121220100 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 1121220100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1707890688).

1121220100 is an abundant number, since it is smaller than the sum of its proper divisors (2294561276).

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

1121220100 is a wasteful number, since it uses less digits than its factorization.

1121220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1121220100 is about 33484.6248299126. The cubic root of 1121220100 is about 1038.8757884010.

Adding to 1121220100 its reverse (10221211), we get a palindrome (1131441311).

The spelling of 1121220100 in words is "one billion, one hundred twenty-one million, two hundred twenty thousand, one hundred".