161311500 has 240 divisors, whose sum is σ = 602521920. Its totient is φ = 36806400.

The previous prime is 161311481. The next prime is 161311517. The reversal of 161311500 is 5113161.

161311500 is a `hidden beast` number, since 1 + 613 + 1 + 1 + 50 + 0 = 666.

161311500 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 283216 + ... + 283784.

It is an arithmetic number, because the mean of its divisors is an integer number (2510508).

Almost surely, 2^161311500 is an apocalyptic number.

161311500 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 161311500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (301260960).

161311500 is an abundant number, since it is smaller than the sum of its proper divisors (441210420).

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

161311500 is a wasteful number, since it uses less digits than its factorization.

161311500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607 (or 586 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

The square root of 161311500 is about 12700.8464284866. The cubic root of 161311500 is about 544.3628049491.

Adding to 161311500 its reverse (5113161), we get a palindrome (166424661).

The spelling of 161311500 in words is "one hundred sixty-one million, three hundred eleven thousand, five hundred".