161665876 has 12 divisors (see below), whose sum is σ = 290561908. Its totient is φ = 78648192.

The previous prime is 161665843. The next prime is 161665897. The reversal of 161665876 is 678566161.

It can be written as a sum of positive squares in 2 ways, for example, as 154504900 + 7160976 = 12430^2 + 2676^2 .

It is a super-2 number, since 2×161665876² = 52271710925694752, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 546021 + ... + 546316.

Almost surely, 2^161665876 is an apocalyptic number.

It is an amenable number.

161665876 is a deficient number, since it is larger than the sum of its proper divisors (128896032).

161665876 is a wasteful number, since it uses less digits than its factorization.

161665876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1092378 (or 1092376 counting only the distinct ones).

The product of its digits is 362880, while the sum is 46.

The square root of 161665876 is about 12714.7896561445. The cubic root of 161665876 is about 544.7611398929.

The spelling of 161665876 in words is "one hundred sixty-one million, six hundred sixty-five thousand, eight hundred seventy-six".