20521163 has 12 divisors (see below), whose sum is σ = 22943808. Its totient is φ = 18326880.

The previous prime is 20521157. The next prime is 20521177. The reversal of 20521163 is 36112502.

It is not a de Polignac number, because 20521163 - 2⁴ = 20521147 is a prime.

It is a super-2 number, since 2×20521163² = 842236261745138, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20521153) 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 11 ways as a sum of consecutive naturals, for example, 3281 + ... + 7197.

It is an arithmetic number, because the mean of its divisors is an integer number (1911984).

Almost surely, 2^20521163 is an apocalyptic number.

20521163 is a deficient number, since it is larger than the sum of its proper divisors (2422645).

20521163 is a wasteful number, since it uses less digits than its factorization.

20521163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3974 (or 3961 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 20521163 is about 4530.0290286046. The cubic root of 20521163 is about 273.7793302046.

Adding to 20521163 its reverse (36112502), we get a palindrome (56633665).

The spelling of 20521163 in words is "twenty million, five hundred twenty-one thousand, one hundred sixty-three".