161768257687 has 4 divisors (see below), whose sum is σ = 162231777400. Its totient is φ = 161304737976.

The previous prime is 161768257667. The next prime is 161768257723. The reversal of 161768257687 is 786752867161.

161768257687 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161768257687 - 2¹¹ = 161768255639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161768257667) 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 in 3 ways as a sum of consecutive naturals, for example, 231759333 + ... + 231760030.

It is an arithmetic number, because the mean of its divisors is an integer number (40557944350).

Almost surely, 2^161768257687 is an apocalyptic number.

161768257687 is a deficient number, since it is larger than the sum of its proper divisors (463519713).

161768257687 is an equidigital number, since it uses as much as digits as its factorization.

161768257687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463519712.

The product of its digits is 47416320, while the sum is 64.

The spelling of 161768257687 in words is "one hundred sixty-one billion, seven hundred sixty-eight million, two hundred fifty-seven thousand, six hundred eighty-seven".