1231011100 has 72 divisors (see below), whose sum is σ = 2957810688. Its totient is φ = 440932800.

The previous prime is 1231011091. The next prime is 1231011107. The reversal of 1231011100 is 11101321.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231011107) 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, 65349 + ... + 82051.

It is an arithmetic number, because the mean of its divisors is an integer number (41080704).

Almost surely, 2^1231011100 is an apocalyptic number.

1231011100 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 1231011100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1478905344).

1231011100 is an abundant number, since it is smaller than the sum of its proper divisors (1726799588).

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

1231011100 is a wasteful number, since it uses less digits than its factorization.

1231011100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16795 (or 16788 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 10.

The square root of 1231011100 is about 35085.7677698522. The cubic root of 1231011100 is about 1071.7347758040.

Adding to 1231011100 its reverse (11101321), we get a palindrome (1242112421).

The spelling of 1231011100 in words is "one billion, two hundred thirty-one million, eleven thousand, one hundred".