1321131100021 has 2 divisors, whose sum is σ = 1321131100022. Its totient is φ = 1321131100020.

The previous prime is 1321131099979. The next prime is 1321131100111. The reversal of 1321131100021 is 1200011311231.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1311173854225 + 9957245796 = 1145065^2 + 99786^2 .

It is an emirp because it is prime and its reverse (1200011311231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1321131100021 - 2¹¹ = 1321131097973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1321131099968 and 1321131100004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321131100921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660565550010 + 660565550011.

It is an arithmetic number, because the mean of its divisors is an integer number (660565550011).

Almost surely, 2^{1321131100021} is an apocalyptic number.

It is an amenable number.

1321131100021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321131100021 is an equidigital number, since it uses as much as digits as its factorization.

1321131100021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 1321131100021 its reverse (1200011311231), we get a palindrome (2521142411252).

The spelling of 1321131100021 in words is "one trillion, three hundred twenty-one billion, one hundred thirty-one million, one hundred thousand, twenty-one".