161663676259961 has 2 divisors, whose sum is σ = 161663676259962. Its totient is φ = 161663676259960.

The previous prime is 161663676259951. The next prime is 161663676259991. The reversal of 161663676259961 is 169952676366161.

161663676259961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93135412147561 + 68528264112400 = 9650669^2 + 8278180^2 .

It is a cyclic number.

It is not a de Polignac number, because 161663676259961 - 2³⁴ = 161646496390777 is a prime.

It is a super-2 number, since 2×161663676259961² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (161663676259951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80831838129980 + 80831838129981.

It is an arithmetic number, because the mean of its divisors is an integer number (80831838129981).

Almost surely, 2^{161663676259961} is an apocalyptic number.

It is an amenable number.

161663676259961 is a deficient number, since it is larger than the sum of its proper divisors (1).

161663676259961 is an equidigital number, since it uses as much as digits as its factorization.

161663676259961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 793618560, while the sum is 74.

The spelling of 161663676259961 in words is "one hundred sixty-one trillion, six hundred sixty-three billion, six hundred seventy-six million, two hundred fifty-nine thousand, nine hundred sixty-one".