161616531553 has 2 divisors, whose sum is σ = 161616531554. Its totient is φ = 161616531552.

The previous prime is 161616531539. The next prime is 161616531607. The reversal of 161616531553 is 355135616161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102971675664 + 58644855889 = 320892^2 + 242167^2 .

It is a cyclic number.

It is not a de Polignac number, because 161616531553 - 2⁵ = 161616531521 is a prime.

It is a super-2 number, since 2×161616531553² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161616531533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80808265776 + 80808265777.

It is an arithmetic number, because the mean of its divisors is an integer number (80808265777).

Almost surely, 2^161616531553 is an apocalyptic number.

It is an amenable number.

161616531553 is a deficient number, since it is larger than the sum of its proper divisors (1).

161616531553 is an equidigital number, since it uses as much as digits as its factorization.

161616531553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 243000, while the sum is 43.

The spelling of 161616531553 in words is "one hundred sixty-one billion, six hundred sixteen million, five hundred thirty-one thousand, five hundred fifty-three".