20640022 has 16 divisors (see below), whose sum is σ = 33652080. Its totient is φ = 9437472.

The previous prime is 20640019. The next prime is 20640047. The reversal of 20640022 is 22004602.

It is a junction number, because it is equal to n+sod(n) for n = 20639978 and 20640005.

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 7 ways as a sum of consecutive naturals, for example, 808 + ... + 6475.

It is an arithmetic number, because the mean of its divisors is an integer number (2103255).

Almost surely, 2^20640022 is an apocalyptic number.

20640022 is a deficient number, since it is larger than the sum of its proper divisors (13012058).

20640022 is a wasteful number, since it uses less digits than its factorization.

20640022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7407.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 20640022 is about 4543.1290978796. The cubic root of 20640022 is about 274.3068914752.

Adding to 20640022 its reverse (22004602), we get a palindrome (42644624).

The spelling of 20640022 in words is "twenty million, six hundred forty thousand, twenty-two".