20801185 has 4 divisors (see below), whose sum is σ = 24961428. Its totient is φ = 16640944.

The previous prime is 20801171. The next prime is 20801191. The reversal of 20801185 is 58110802.

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 10764961 + 10036224 = 3281^2 + 3168^2 .

It is a cyclic number.

It is not a de Polignac number, because 20801185 - 2⁷ = 20801057 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2080114 + ... + 2080123.

It is an arithmetic number, because the mean of its divisors is an integer number (6240357).

Almost surely, 2^20801185 is an apocalyptic number.

It is an amenable number.

20801185 is a deficient number, since it is larger than the sum of its proper divisors (4160243).

20801185 is an equidigital number, since it uses as much as digits as its factorization.

20801185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4160242.

The product of its (nonzero) digits is 640, while the sum is 25.

The square root of 20801185 is about 4560.8316127654. The cubic root of 20801185 is about 275.0189959330.

Adding to 20801185 its reverse (58110802), we get a palindrome (78911987).

The spelling of 20801185 in words is "twenty million, eight hundred one thousand, one hundred eighty-five".