161664845 has 16 divisors (see below), whose sum is σ = 205148160. Its totient is φ = 122102400.

The previous prime is 161664829. The next prime is 161664847. The reversal of 161664845 is 548466161.

It is not a de Polignac number, because 161664845 - 2⁴ = 161664829 is a prime.

It is a super-2 number, since 2×161664845² = 52271044217748050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161664847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6365 + ... + 19074.

It is an arithmetic number, because the mean of its divisors is an integer number (12821760).

Almost surely, 2^161664845 is an apocalyptic number.

It is an amenable number.

161664845 is a deficient number, since it is larger than the sum of its proper divisors (43483315).

161664845 is a wasteful number, since it uses less digits than its factorization.

161664845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25516.

The product of its digits is 138240, while the sum is 41.

The square root of 161664845 is about 12714.7491127430. The cubic root of 161664845 is about 544.7599818462.

The spelling of 161664845 in words is "one hundred sixty-one million, six hundred sixty-four thousand, eight hundred forty-five".