20688004 has 6 divisors (see below), whose sum is σ = 36204014. Its totient is φ = 10344000.

The previous prime is 20688001. The next prime is 20688007. The reversal of 20688004 is 40088602.

It is an interprime number because it is at equal distance from previous prime (20688001) and next prime (20688007).

It can be written as a sum of positive squares in only one way, i.e., 19342404 + 1345600 = 4398^2 + 1160^2 .

It is not an unprimeable number, because it can be changed into a prime (20688001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2585997 + ... + 2586004.

Almost surely, 2^20688004 is an apocalyptic number.

It is an amenable number.

20688004 is a deficient number, since it is larger than the sum of its proper divisors (15516010).

20688004 is a wasteful number, since it uses less digits than its factorization.

20688004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5172005 (or 5172003 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 20688004 is about 4548.4067540184. The cubic root of 20688004 is about 274.5192880078.

The spelling of 20688004 in words is "twenty million, six hundred eighty-eight thousand, four".