20380181 has 4 divisors (see below), whose sum is σ = 20401164. Its totient is φ = 20359200.

The previous prime is 20380177. The next prime is 20380207. The reversal of 20380181 is 18108302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15928081 + 4452100 = 3991^2 + 2110^2 .

It is a cyclic number.

It is not a de Polignac number, because 20380181 - 2² = 20380177 is a prime.

It is a super-2 number, since 2×20380181² = 830703555185522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20380111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8960 + ... + 11001.

It is an arithmetic number, because the mean of its divisors is an integer number (5100291).

Almost surely, 2^20380181 is an apocalyptic number.

It is an amenable number.

20380181 is a deficient number, since it is larger than the sum of its proper divisors (20983).

20380181 is a wasteful number, since it uses less digits than its factorization.

20380181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20982.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 20380181 is about 4514.4413829399. The cubic root of 20380181 is about 273.1509271137.

Adding to 20380181 its reverse (18108302), we get a palindrome (38488483).

The spelling of 20380181 in words is "twenty million, three hundred eighty thousand, one hundred eighty-one".