1231200100 has 72 divisors (see below), whose sum is σ = 2906017128. Its totient is φ = 450048000.

The previous prime is 1231200083. The next prime is 1231200119. The reversal of 1231200100 is 10021321.

It can be written as a sum of positive squares in 12 ways, for example, as 463799296 + 767400804 = 21536^2 + 27702^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 126612 + ... + 135988.

It is an arithmetic number, because the mean of its divisors is an integer number (40361349).

Almost surely, 2^1231200100 is an apocalyptic number.

1231200100 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 1231200100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1453008564).

1231200100 is an abundant number, since it is smaller than the sum of its proper divisors (1674817028).

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

1231200100 is a wasteful number, since it uses less digits than its factorization.

1231200100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9505 (or 9498 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 1231200100 is about 35088.4610662822. The cubic root of 1231200100 is about 1071.7896216423.

Adding to 1231200100 its reverse (10021321), we get a palindrome (1241221421).

The spelling of 1231200100 in words is "one billion, two hundred thirty-one million, two hundred thousand, one hundred".