20206181 has 8 divisors (see below), whose sum is σ = 21039384. Its totient is φ = 19388160.

The previous prime is 20206171. The next prime is 20206187. The reversal of 20206181 is 18160202.

It can be written as a sum of positive squares in 4 ways, for example, as 11621281 + 8584900 = 3409^2 + 2930^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20206181 - 2¹⁴ = 20189797 is a prime.

It is a super-2 number, since 2×20206181² = 816579501209522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20206187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1040 + ... + 6441.

It is an arithmetic number, because the mean of its divisors is an integer number (2629923).

Almost surely, 2^20206181 is an apocalyptic number.

It is an amenable number.

20206181 is a deficient number, since it is larger than the sum of its proper divisors (833203).

20206181 is an equidigital number, since it uses as much as digits as its factorization.

20206181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7591.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 20206181 is about 4495.1285854801. The cubic root of 20206181 is about 272.3713434692.

Adding to 20206181 its reverse (18160202), we get a palindrome (38366383).

The spelling of 20206181 in words is "twenty million, two hundred six thousand, one hundred eighty-one".