161968609639 has 2 divisors, whose sum is σ = 161968609640. Its totient is φ = 161968609638.

The previous prime is 161968609609. The next prime is 161968609643. The reversal of 161968609639 is 936906869161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161968609639 - 2¹⁹ = 161968085351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161968609609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80984304819 + 80984304820.

It is an arithmetic number, because the mean of its divisors is an integer number (80984304820).

Almost surely, 2^161968609639 is an apocalyptic number.

161968609639 is a deficient number, since it is larger than the sum of its proper divisors (1).

161968609639 is an equidigital number, since it uses as much as digits as its factorization.

161968609639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22674816, while the sum is 64.

The spelling of 161968609639 in words is "one hundred sixty-one billion, nine hundred sixty-eight million, six hundred nine thousand, six hundred thirty-nine".