1321011200021 has 4 divisors (see below), whose sum is σ = 1322729030700. Its totient is φ = 1319293369344.

The previous prime is 1321011199987. The next prime is 1321011200029. The reversal of 1321011200021 is 1200021101231.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 368796285796 + 952214914225 = 607286^2 + 975815^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321011200021 - 2⁶ = 1321011199957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321011199969 and 1321011200005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321011200029) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 858914186 + ... + 858915723.

It is an arithmetic number, because the mean of its divisors is an integer number (330682257675).

Almost surely, 2^{1321011200021} is an apocalyptic number.

It is an amenable number.

1321011200021 is a deficient number, since it is larger than the sum of its proper divisors (1717830679).

1321011200021 is an equidigital number, since it uses as much as digits as its factorization.

1321011200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1717830678.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 1321011200021 its reverse (1200021101231), we get a palindrome (2521032301252).

The spelling of 1321011200021 in words is "one trillion, three hundred twenty-one billion, eleven million, two hundred thousand, twenty-one".