161367659681 has 2 divisors, whose sum is σ = 161367659682. Its totient is φ = 161367659680.

The previous prime is 161367659671. The next prime is 161367659759. The reversal of 161367659681 is 186956763161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153475114081 + 7892545600 = 391759^2 + 88840^2 .

It is a cyclic number.

It is not a de Polignac number, because 161367659681 - 2⁶ = 161367659617 is a prime.

It is a super-2 number, since 2×161367659681² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161367659681.

It is not a weakly prime, because it can be changed into another prime (161367659671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80683829840 + 80683829841.

It is an arithmetic number, because the mean of its divisors is an integer number (80683829841).

Almost surely, 2^161367659681 is an apocalyptic number.

It is an amenable number.

161367659681 is a deficient number, since it is larger than the sum of its proper divisors (1).

161367659681 is an equidigital number, since it uses as much as digits as its factorization.

161367659681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9797760, while the sum is 59.

The spelling of 161367659681 in words is "one hundred sixty-one billion, three hundred sixty-seven million, six hundred fifty-nine thousand, six hundred eighty-one".