181620 has 36 divisors (see below), whose sum is σ = 551460. Its totient is φ = 48384.

The previous prime is 181619. The next prime is 181639. The reversal of 181620 is 26181.

181620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 60516 + 121104 = 246^2 + 348^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a plaindrome in base 11.

It is a zygodrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 181593 and 181602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 325 + ... + 684.

2¹⁸¹⁶²⁰ is an apocalyptic number.

181620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181620 is an abundant number, since it is smaller than the sum of its proper divisors (369840).

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

181620 is a wasteful number, since it uses less digits than its factorization.

181620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1024 (or 1019 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 181620 is about 426.1689805699. The cubic root of 181620 is about 56.6310425843.

The spelling of 181620 in words is "one hundred eighty-one thousand, six hundred twenty".