20868558 has 16 divisors (see below), whose sum is σ = 41783040. Its totient is φ = 6948536.

The previous prime is 20868539. The next prime is 20868559. The reversal of 20868558 is 85586802.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20868559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7753 + ... + 10091.

It is an arithmetic number, because the mean of its divisors is an integer number (2611440).

Almost surely, 2^20868558 is an apocalyptic number.

20868558 is an abundant number, since it is smaller than the sum of its proper divisors (20914482).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20868558 is a wasteful number, since it uses less digits than its factorization.

20868558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3831.

The product of its (nonzero) digits is 153600, while the sum is 42.

The square root of 20868558 is about 4568.2116851127. The cubic root of 20868558 is about 275.3155958038.

The spelling of 20868558 in words is "twenty million, eight hundred sixty-eight thousand, five hundred fifty-eight".