161601664 has 128 divisors (see below), whose sum is σ = 388644480. Its totient is φ = 65495040.

The previous prime is 161601653. The next prime is 161601679. The reversal of 161601664 is 466106161.

161601664 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×161601664² = 52230195615137792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1946967 + ... + 1947049.

It is an arithmetic number, because the mean of its divisors is an integer number (3036285).

Almost surely, 2^161601664 is an apocalyptic number.

161601664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161601664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (194322240).

161601664 is an abundant number, since it is smaller than the sum of its proper divisors (227042816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161601664 is an equidigital number, since it uses as much as digits as its factorization.

161601664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 186 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 161601664 is about 12712.2643144327. The cubic root of 161601664 is about 544.6890058606.

The spelling of 161601664 in words is "one hundred sixty-one million, six hundred one thousand, six hundred sixty-four".