5531321531621 has 2 divisors, whose sum is σ = 5531321531622. Its totient is φ = 5531321531620.

The previous prime is 5531321531611. The next prime is 5531321531627. The reversal of 5531321531621 is 1261351231355.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4472861227396 + 1058460304225 = 2114914^2 + 1028815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5531321531621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5531321531627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2765660765810 + 2765660765811.

It is an arithmetic number, because the mean of its divisors is an integer number (2765660765811).

Almost surely, 2^{5531321531621} is an apocalyptic number.

It is an amenable number.

5531321531621 is a deficient number, since it is larger than the sum of its proper divisors (1).

5531321531621 is an equidigital number, since it uses as much as digits as its factorization.

5531321531621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81000, while the sum is 38.

Adding to 5531321531621 its reverse (1261351231355), we get a palindrome (6792672762976).

The spelling of 5531321531621 in words is "five trillion, five hundred thirty-one billion, three hundred twenty-one million, five hundred thirty-one thousand, six hundred twenty-one".