1321322100 has 144 divisors (see below), whose sum is σ = 4395635328. Its totient is φ = 300188160.

The previous prime is 1321322077. The next prime is 1321322137. The reversal of 1321322100 is 12231231.

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 1321322100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 361482 + ... + 365118.

Almost surely, 2^1321322100 is an apocalyptic number.

1321322100 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 1321322100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2197817664).

1321322100 is an abundant number, since it is smaller than the sum of its proper divisors (3074313228).

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

1321322100 is a wasteful number, since it uses less digits than its factorization.

1321322100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3834 (or 3827 counting only the distinct ones).

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

The square root of 1321322100 is about 36349.9944979363. The cubic root of 1321322100 is about 1097.3274237739.

Adding to 1321322100 its reverse (12231231), we get a palindrome (1333553331).

The spelling of 1321322100 in words is "one billion, three hundred twenty-one million, three hundred twenty-two thousand, one hundred".