1321011020100 has 72 divisors (see below), whose sum is σ = 3825610332768. Its totient is φ = 351948396800.

The previous prime is 1321011020093. The next prime is 1321011020101. The reversal of 1321011020100 is 10201101231.

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 (1321011020101) 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, 1677906 + ... + 2336105.

It is an arithmetic number, because the mean of its divisors is an integer number (53133476844).

Almost surely, 2^{1321011020100} is an apocalyptic number.

1321011020100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321011020100 is an abundant number, since it is smaller than the sum of its proper divisors (2504599312668).

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

1321011020100 is a wasteful number, since it uses less digits than its factorization.

1321011020100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4015125 (or 4015118 counting only the distinct ones).

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

Adding to 1321011020100 its reverse (10201101231), we get a palindrome (1331212121331).

The spelling of 1321011020100 in words is "one trillion, three hundred twenty-one billion, eleven million, twenty thousand, one hundred".