1201211100 has 72 divisors (see below), whose sum is σ = 3861679920. Its totient is φ = 320322240.

The previous prime is 1201211069. The next prime is 1201211107. The reversal of 1201211100 is 11121021.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201211107) 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, 219747 + ... + 225146.

Almost surely, 2^1201211100 is an apocalyptic number.

1201211100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1201211100 is an abundant number, since it is smaller than the sum of its proper divisors (2660468820).

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

1201211100 is a wasteful number, since it uses less digits than its factorization.

1201211100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444916 (or 444903 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1201211100 is about 34658.4924657724. The cubic root of 1201211100 is about 1063.0159450360.

Adding to 1201211100 its reverse (11121021), we get a palindrome (1212332121).

The spelling of 1201211100 in words is "one billion, two hundred one million, two hundred eleven thousand, one hundred".