161011800 has 144 divisors (see below), whose sum is σ = 560927640. Its totient is φ = 42923520.

The previous prime is 161011771. The next prime is 161011813. The reversal of 161011800 is 8110161.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 46944 + ... + 50256.

Almost surely, 2^161011800 is an apocalyptic number.

161011800 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 161011800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280463820).

161011800 is an abundant number, since it is smaller than the sum of its proper divisors (399915840).

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

161011800 is a wasteful number, since it uses less digits than its factorization.

161011800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3344 (or 3323 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

The square root of 161011800 is about 12689.0425170696. The cubic root of 161011800 is about 544.0254727836.

Adding to 161011800 its reverse (8110161), we get a palindrome (169121961).

The spelling of 161011800 in words is "one hundred sixty-one million, eleven thousand, eight hundred".