20001996 has 216 divisors, whose sum is σ = 67223520. Its totient is φ = 4967424.

The previous prime is 20001983. The next prime is 20002007. The reversal of 20001996 is 69910002.

20001996 = 1² + 2² + ... + 391².

It is a happy number.

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 689710 + ... + 689738.

It is an arithmetic number, because the mean of its divisors is an integer number (311220).

Almost surely, 2^20001996 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 20001996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33611760).

20001996 is an abundant number, since it is smaller than the sum of its proper divisors (47221524).

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

20001996 is a wasteful number, since it uses less digits than its factorization.

20001996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 81 counting only the distinct ones).

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

The square root of 20001996 is about 4472.3591090162. The cubic root of 20001996 is about 271.4507913217.

Adding to 20001996 its reverse (69910002), we get a palindrome (89911998).

The spelling of 20001996 in words is "twenty million, one thousand, nine hundred ninety-six".