161868626641 has 2 divisors, whose sum is σ = 161868626642. Its totient is φ = 161868626640.

The previous prime is 161868626593. The next prime is 161868626653. The reversal of 161868626641 is 146626868161.

It is a happy number.

161868626641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148483062225 + 13385564416 = 385335^2 + 115696^2 .

It is a cyclic number.

It is not a de Polignac number, because 161868626641 - 2²⁹ = 161331755729 is a prime.

It is not a weakly prime, because it can be changed into another prime (161868636641) 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, 80934313320 + 80934313321.

It is an arithmetic number, because the mean of its divisors is an integer number (80934313321).

Almost surely, 2^161868626641 is an apocalyptic number.

It is an amenable number.

161868626641 is a deficient number, since it is larger than the sum of its proper divisors (1).

161868626641 is an equidigital number, since it uses as much as digits as its factorization.

161868626641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3981312, while the sum is 55.

The spelling of 161868626641 in words is "one hundred sixty-one billion, eight hundred sixty-eight million, six hundred twenty-six thousand, six hundred forty-one".