181820001 has 32 divisors (see below), whose sum is σ = 270950400. Its totient is φ = 107527680.

The previous prime is 181819933. The next prime is 181820033. The reversal of 181820001 is 100028181.

181820001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 181820001 - 2¹⁰ = 181818977 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 181820001.

It is not an unprimeable number, because it can be changed into a prime (181820501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 252520 + ... + 253238.

It is an arithmetic number, because the mean of its divisors is an integer number (8467200).

Almost surely, 2^181820001 is an apocalyptic number.

181820001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

181820001 is a deficient number, since it is larger than the sum of its proper divisors (89130399).

181820001 is a wasteful number, since it uses less digits than its factorization.

181820001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909.

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

The square root of 181820001 is about 13484.0647061633. The cubic root of 181820001 is about 566.5182243628.

Adding to 181820001 its reverse (100028181), we get a palindrome (281848182).

The spelling of 181820001 in words is "one hundred eighty-one million, eight hundred twenty thousand, one".