161997760 has 112 divisors (see below), whose sum is σ = 414003744. Its totient is φ = 60162048.

The previous prime is 161997757. The next prime is 161997769. The reversal of 161997760 is 67799161.

161997760 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 161997760.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161997769) 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, 527527 + ... + 527833.

It is an arithmetic number, because the mean of its divisors is an integer number (3696462).

Almost surely, 2^161997760 is an apocalyptic number.

161997760 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 161997760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207001872).

161997760 is an abundant number, since it is smaller than the sum of its proper divisors (252005984).

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

161997760 is a wasteful number, since it uses less digits than its factorization.

161997760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 46.

The square root of 161997760 is about 12727.8340655431. The cubic root of 161997760 is about 545.1336652763.

The spelling of 161997760 in words is "one hundred sixty-one million, nine hundred ninety-seven thousand, seven hundred sixty".