20109986 has 12 divisors (see below), whose sum is σ = 32664402. Its totient is φ = 9281376.

The previous prime is 20109977. The next prime is 20109989. The reversal of 20109986 is 68990102.

It can be written as a sum of positive squares in 3 ways, for example, as 10923025 + 9186961 = 3305^2 + 3031^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20109989) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 29411 + ... + 30086.

Almost surely, 2^20109986 is an apocalyptic number.

20109986 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20109986 is a deficient number, since it is larger than the sum of its proper divisors (12554416).

20109986 is a wasteful number, since it uses less digits than its factorization.

20109986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59525 (or 59512 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 20109986 is about 4484.4159039946. The cubic root of 20109986 is about 271.9384322156.

The spelling of 20109986 in words is "twenty million, one hundred nine thousand, nine hundred eighty-six".