20180181 has 8 divisors (see below), whose sum is σ = 30750784. Its totient is φ = 11531520.

The previous prime is 20180179. The next prime is 20180189. The reversal of 20180181 is 18108102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20180181 - 2¹ = 20180179 is a prime.

It is a super-2 number, since 2×20180181² = 814479410385522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 960961 = 20180181 / (2 + 0 + 1 + 8 + 0 + 1 + 8 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20180189) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 480460 + ... + 480501.

It is an arithmetic number, because the mean of its divisors is an integer number (3843848).

Almost surely, 2^20180181 is an apocalyptic number.

20180181 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20180181 is a deficient number, since it is larger than the sum of its proper divisors (10570603).

20180181 is an equidigital number, since it uses as much as digits as its factorization.

20180181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 960971.

The product of its (nonzero) digits is 128, while the sum is 21.

The square root of 20180181 is about 4492.2356349595. The cubic root of 20180181 is about 272.2544700810.

Adding to 20180181 its reverse (18108102), we get a palindrome (38288283).

The spelling of 20180181 in words is "twenty million, one hundred eighty thousand, one hundred eighty-one".