20640052 has 12 divisors (see below), whose sum is σ = 36168160. Its totient is φ = 10306296.

The previous prime is 20640049. The next prime is 20640071. The reversal of 20640052 is 25004602.

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 3 ways as a sum of consecutive naturals, for example, 433 + ... + 6439.

Almost surely, 2^20640052 is an apocalyptic number.

It is an amenable number.

20640052 is a deficient number, since it is larger than the sum of its proper divisors (15528108).

20640052 is a wasteful number, since it uses less digits than its factorization.

20640052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6870 (or 6868 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20640052 is about 4543.1323995675. The cubic root of 20640052 is about 274.3070243756.

Adding to 20640052 its reverse (25004602), we get a palindrome (45644654).

The spelling of 20640052 in words is "twenty million, six hundred forty thousand, fifty-two".