20531986 has 8 divisors (see below), whose sum is σ = 30976524. Its totient is φ = 10206480.

The previous prime is 20531983. The next prime is 20531999. The reversal of 20531986 is 68913502.

It can be written as a sum of positive squares in 2 ways, for example, as 20529961 + 2025 = 4531^2 + 45^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (20531981) 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 3 ways as a sum of consecutive naturals, for example, 29325 + ... + 30016.

Almost surely, 2^20531986 is an apocalyptic number.

20531986 is a deficient number, since it is larger than the sum of its proper divisors (10444538).

20531986 is a wasteful number, since it uses less digits than its factorization.

20531986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59516.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 20531986 is about 4531.2234550947. The cubic root of 20531986 is about 273.8274527683.

The spelling of 20531986 in words is "twenty million, five hundred thirty-one thousand, nine hundred eighty-six".