1321021100100 has 216 divisors, whose sum is σ = 4140556049952. Its totient is φ = 325035110400.

The previous prime is 1321021100089. The next prime is 1321021100107. The reversal of 1321021100100 is 10011201231.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (1321021100107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 168472180 + ... + 168480020.

It is an arithmetic number, because the mean of its divisors is an integer number (19169240972).

Almost surely, 2^{1321021100100} is an apocalyptic number.

1321021100100 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 1321021100100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2070278024976).

1321021100100 is an abundant number, since it is smaller than the sum of its proper divisors (2819534949852).

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

1321021100100 is a wasteful number, since it uses less digits than its factorization.

1321021100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11207 (or 11187 counting only the distinct ones).

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

Adding to 1321021100100 its reverse (10011201231), we get a palindrome (1331032301331).

The spelling of 1321021100100 in words is "one trillion, three hundred twenty-one billion, twenty-one million, one hundred thousand, one hundred".