161873920 has 144 divisors (see below), whose sum is σ = 440400240. Its totient is φ = 56623104.

The previous prime is 161873903. The next prime is 161873953. The reversal of 161873920 is 29378161.

It is a self number, because there is not a number n which added to its sum of digits gives 161873920.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8519671 + ... + 8519689.

It is an arithmetic number, because the mean of its divisors is an integer number (3058335).

Almost surely, 2^161873920 is an apocalyptic number.

161873920 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 161873920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220200120).

161873920 is an abundant number, since it is smaller than the sum of its proper divisors (278526320).

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

161873920 is an frugal number, since it uses more digits than its factorization.

161873920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71 (or 39 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 161873920 is about 12722.9682071441. The cubic root of 161873920 is about 544.9947198097.

The spelling of 161873920 in words is "one hundred sixty-one million, eight hundred seventy-three thousand, nine hundred twenty".