1321220132100 has 864 divisors, whose sum is σ = 4967940781440. Its totient is φ = 289916928000.

The previous prime is 1321220132077. The next prime is 1321220132107. The reversal of 1321220132100 is 12310221231.

1321220132100 is a `hidden beast` number, since 1 + 321 + 2 + 20 + 1 + 321 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (1321220132107) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 2054774379 + ... + 2054775021.

It is an arithmetic number, because the mean of its divisors is an integer number (5749931460).

Almost surely, 2^{1321220132100} is an apocalyptic number.

1321220132100 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 1321220132100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2483970390720).

1321220132100 is an abundant number, since it is smaller than the sum of its proper divisors (3646720649340).

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

1321220132100 is a wasteful number, since it uses less digits than its factorization.

1321220132100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1141 (or 1131 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 1321220132100 its reverse (12310221231), we get a palindrome (1333530353331).

The spelling of 1321220132100 in words is "one trillion, three hundred twenty-one billion, two hundred twenty million, one hundred thirty-two thousand, one hundred".