20558881 has 24 divisors (see below), whose sum is σ = 24952320. Its totient is φ = 16877952.

The previous prime is 20558861. The next prime is 20558897. The reversal of 20558881 is 18885502.

It is not a de Polignac number, because 20558881 - 2¹⁹ = 20034593 is a prime.

It is a super-4 number, since 4×20558881⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20558881.

It is not an unprimeable number, because it can be changed into a prime (20558821) 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 23 ways as a sum of consecutive naturals, for example, 181881 + ... + 181993.

It is an arithmetic number, because the mean of its divisors is an integer number (1039680).

Almost surely, 2^20558881 is an apocalyptic number.

It is an amenable number.

20558881 is a deficient number, since it is larger than the sum of its proper divisors (4393439).

20558881 is a wasteful number, since it uses less digits than its factorization.

20558881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 37.

The square root of 20558881 is about 4534.1902253875. The cubic root of 20558881 is about 273.9469634680.

The spelling of 20558881 in words is "twenty million, five hundred fifty-eight thousand, eight hundred eighty-one".