20581116 has 24 divisors (see below), whose sum is σ = 48244224. Its totient is φ = 6828720.

The previous prime is 20581103. The next prime is 20581153. The reversal of 20581116 is 61118502.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 1170 + ... + 6521.

It is an arithmetic number, because the mean of its divisors is an integer number (2010176).

Almost surely, 2^20581116 is an apocalyptic number.

It is an amenable number.

20581116 is an abundant number, since it is smaller than the sum of its proper divisors (27663108).

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

20581116 is a wasteful number, since it uses less digits than its factorization.

20581116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7921 (or 7919 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 20581116 is about 4536.6414890313. The cubic root of 20581116 is about 274.0456882983.

Adding to 20581116 its reverse (61118502), we get a palindrome (81699618).

The spelling of 20581116 in words is "twenty million, five hundred eighty-one thousand, one hundred sixteen".