20108986 has 4 divisors (see below), whose sum is σ = 30163482. Its totient is φ = 10054492.

The previous prime is 20108981. The next prime is 20108989. The reversal of 20108986 is 68980102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68980102 = 2 ⋅34490051.

It can be written as a sum of positive squares in only one way, i.e., 12737761 + 7371225 = 3569^2 + 2715^2 .

It is not an unprimeable number, because it can be changed into a prime (20108981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5027245 + ... + 5027248.

Almost surely, 2^20108986 is an apocalyptic number.

20108986 is a deficient number, since it is larger than the sum of its proper divisors (10054496).

20108986 is a wasteful number, since it uses less digits than its factorization.

20108986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10054495.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 20108986 is about 4484.3044053677. The cubic root of 20108986 is about 271.9339246218.

The spelling of 20108986 in words is "twenty million, one hundred eight thousand, nine hundred eighty-six".