1201220100 has 108 divisors (see below), whose sum is σ = 3790521280. Its totient is φ = 318168000.

The previous prime is 1201220087. The next prime is 1201220129. The reversal of 1201220100 is 10221021.

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 131481 + ... + 140319.

Almost surely, 2^1201220100 is an apocalyptic number.

1201220100 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 1201220100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1895260640).

1201220100 is an abundant number, since it is smaller than the sum of its proper divisors (2589301180).

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

1201220100 is a wasteful number, since it uses less digits than its factorization.

1201220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9010 (or 9000 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1201220100 is about 34658.6223038366. The cubic root of 1201220100 is about 1063.0185998898.

Adding to 1201220100 its reverse (10221021), we get a palindrome (1211441121).

The spelling of 1201220100 in words is "one billion, two hundred one million, two hundred twenty thousand, one hundred".