20731116 has 36 divisors (see below), whose sum is σ = 56271768. Its totient is φ = 5923008.

The previous prime is 20731097. The next prime is 20731121. The reversal of 20731116 is 61113702.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 20731092 and 20731101.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17041 + ... + 18216.

Almost surely, 2^20731116 is an apocalyptic number.

It is an amenable number.

20731116 is an abundant number, since it is smaller than the sum of its proper divisors (35540652).

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

20731116 is a wasteful number, since it uses less digits than its factorization.

20731116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35278 (or 35269 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 20731116 is about 4553.1435294750. The cubic root of 20731116 is about 274.7098471350.

Adding to 20731116 its reverse (61113702), we get a palindrome (81844818).

The spelling of 20731116 in words is "twenty million, seven hundred thirty-one thousand, one hundred sixteen".