20007904 has 48 divisors (see below), whose sum is σ = 45360000. Its totient is φ = 8509824.

The previous prime is 20007881. The next prime is 20007919. The reversal of 20007904 is 40970002.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 39847 + ... + 40345.

It is an arithmetic number, because the mean of its divisors is an integer number (945000).

Almost surely, 2^20007904 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 20007904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22680000).

20007904 is an abundant number, since it is smaller than the sum of its proper divisors (25352096).

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

20007904 is a wasteful number, since it uses less digits than its factorization.

20007904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 20007904 is about 4473.0195617726. The cubic root of 20007904 is about 271.4775148781.

Adding to 20007904 its reverse (40970002), we get a palindrome (60977906).

The spelling of 20007904 in words is "twenty million, seven thousand, nine hundred four".