20009916 has 60 divisors (see below), whose sum is σ = 52785040. Its totient is φ = 6609600.

The previous prime is 20009887. The next prime is 20009917. The reversal of 20009916 is 61990002.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 20009916.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20009917) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 48720 + ... + 49128.

Almost surely, 2^20009916 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20009916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26392520).

20009916 is an abundant number, since it is smaller than the sum of its proper divisors (32775124).

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

20009916 is a wasteful number, since it uses less digits than its factorization.

20009916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576 (or 565 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 20009916 is about 4473.2444601206. The cubic root of 20009916 is about 271.4866145228.

Adding to 20009916 its reverse (61990002), we get a palindrome (81999918).

The spelling of 20009916 in words is "twenty million, nine thousand, nine hundred sixteen".