1231322100 has 72 divisors (see below), whose sum is σ = 3571229760. Its totient is φ = 327559680.

The previous prime is 1231322041. The next prime is 1231322111. The reversal of 1231322100 is 12231321.

It is a super-2 number, since 2×1231322100² = 3032308227896820000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1231322100.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 125161 + ... + 134639.

Almost surely, 2^1231322100 is an apocalyptic number.

1231322100 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 1231322100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1785614880).

1231322100 is an abundant number, since it is smaller than the sum of its proper divisors (2339907660).

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

1231322100 is a wasteful number, since it uses less digits than its factorization.

1231322100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9929 (or 9922 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1231322100 is about 35090.1994864663. The cubic root of 1231322100 is about 1071.8250217951.

Adding to 1231322100 its reverse (12231321), we get a palindrome (1243553421).

The spelling of 1231322100 in words is "one billion, two hundred thirty-one million, three hundred twenty-two thousand, one hundred".