1613511821321 has 2 divisors, whose sum is σ = 1613511821322. Its totient is φ = 1613511821320.

The previous prime is 1613511821191. The next prime is 1613511821359. The reversal of 1613511821321 is 1231281153161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 830394787600 + 783117033721 = 911260^2 + 884939^2 .

It is a cyclic number.

It is not a de Polignac number, because 1613511821321 - 2³⁸ = 1338633914377 is a prime.

It is a super-2 number, since 2×1613511821321² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1613511881321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 806755910660 + 806755910661.

It is an arithmetic number, because the mean of its divisors is an integer number (806755910661).

Almost surely, 2^{1613511821321} is an apocalyptic number.

It is an amenable number.

1613511821321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1613511821321 is an equidigital number, since it uses as much as digits as its factorization.

1613511821321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 35.

Adding to 1613511821321 its reverse (1231281153161), we get a palindrome (2844792974482).

The spelling of 1613511821321 in words is "one trillion, six hundred thirteen billion, five hundred eleven million, eight hundred twenty-one thousand, three hundred twenty-one".