20021181 has 8 divisors (see below), whose sum is σ = 27416544. Its totient is φ = 12986640.

The previous prime is 20021171. The next prime is 20021203. The reversal of 20021181 is 18112002.

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

It is not a de Polignac number, because 20021181 - 2¹⁰ = 20020157 is a prime.

It is a super-2 number, since 2×20021181² = 801695377269522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20021181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90075 + ... + 90296.

It is an arithmetic number, because the mean of its divisors is an integer number (3427068).

Almost surely, 2^20021181 is an apocalyptic number.

It is an amenable number.

20021181 is a deficient number, since it is larger than the sum of its proper divisors (7395363).

20021181 is a wasteful number, since it uses less digits than its factorization.

20021181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180411.

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 20021181 is about 4474.5034361368. The cubic root of 20021181 is about 271.5375513180.

Adding to 20021181 its reverse (18112002), we get a palindrome (38133183).

It can be divided in two parts, 20021 and 181, that added together give a palindrome (20202).

The spelling of 20021181 in words is "twenty million, twenty-one thousand, one hundred eighty-one".