161920 has 64 divisors (see below), whose sum is σ = 440640. Its totient is φ = 56320.

The previous prime is 161911. The next prime is 161921. The reversal of 161920 is 29161.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161921) by changing a digit.

161920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7029 + ... + 7051.

It is an arithmetic number, because the mean of its divisors is an integer number (6885).

2¹⁶¹⁹²⁰ is an apocalyptic number.

161920 is a gapful number since it is divisible by the number (10) 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 161920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220320).

161920 is an abundant number, since it is smaller than the sum of its proper divisors (278720).

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

161920 is a wasteful number, since it uses less digits than its factorization.

161920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 161920 is about 402.3928428787. The cubic root of 161920 is about 54.5046428724.

It can be divided in two parts, 161 and 920, that added together give a triangular number (1081 = T₄₆).

The spelling of 161920 in words is "one hundred sixty-one thousand, nine hundred twenty".