181020 has 48 divisors (see below), whose sum is σ = 580608. Its totient is φ = 41280.

The previous prime is 181019. The next prime is 181031. The reversal of 181020 is 20181.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 180987 and 181005.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 181020.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 205 + ... + 635.

It is an arithmetic number, because the mean of its divisors is an integer number (12096).

2¹⁸¹⁰²⁰ is an apocalyptic number.

181020 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 181020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (290304).

181020 is an abundant number, since it is smaller than the sum of its proper divisors (399588).

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

181020 is a wasteful number, since it uses less digits than its factorization.

181020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450 (or 448 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 181020 is about 425.4644520991. The cubic root of 181020 is about 56.5686116632.

It can be divided in two parts, 1810 and 20, that added together give a triangular number (1830 = T₆₀).

The spelling of 181020 in words is "one hundred eighty-one thousand, twenty".