161668705 has 24 divisors (see below), whose sum is σ = 214128936. Its totient is φ = 117089280.

The previous prime is 161668667. The next prime is 161668721. The reversal of 161668705 is 507866161.

161668705 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 17380561 + 144288144 = 4169^2 + 12012^2 .

It is a de Polignac number, because none of the positive numbers 2^k-161668705 is a prime.

It is a super-2 number, since 2×161668705² = 52273540352754050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 213187 + ... + 213943.

It is an arithmetic number, because the mean of its divisors is an integer number (8922039).

Almost surely, 2^161668705 is an apocalyptic number.

It is an amenable number.

161668705 is a deficient number, since it is larger than the sum of its proper divisors (52460231).

161668705 is a wasteful number, since it uses less digits than its factorization.

161668705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1137 (or 1126 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 161668705 is about 12714.9009040574. The cubic root of 161668705 is about 544.7643174760.

It can be divided in two parts, 161 and 668705, that added together give a palindrome (668866).

The spelling of 161668705 in words is "one hundred sixty-one million, six hundred sixty-eight thousand, seven hundred five".