161885687 has 2 divisors, whose sum is σ = 161885688. Its totient is φ = 161885686.

The previous prime is 161885663. The next prime is 161885771. The reversal of 161885687 is 786588161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161885687 - 2⁶ = 161885623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161885617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80942843 + 80942844.

It is an arithmetic number, because the mean of its divisors is an integer number (80942844).

Almost surely, 2^161885687 is an apocalyptic number.

161885687 is a deficient number, since it is larger than the sum of its proper divisors (1).

161885687 is an equidigital number, since it uses as much as digits as its factorization.

161885687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 645120, while the sum is 50.

The square root of 161885687 is about 12723.4306301406. The cubic root of 161885687 is about 545.0079251436.

The spelling of 161885687 in words is "one hundred sixty-one million, eight hundred eighty-five thousand, six hundred eighty-seven".