20640230 has 16 divisors (see below), whose sum is σ = 40010544. Its totient is φ = 7620960.

The previous prime is 20640181. The next prime is 20640233. The reversal of 20640230 is 3204602.

It is a junction number, because it is equal to n+sod(n) for n = 20640199 and 20640208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20640233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79256 + ... + 79515.

It is an arithmetic number, because the mean of its divisors is an integer number (2500659).

Almost surely, 2^20640230 is an apocalyptic number.

20640230 is a deficient number, since it is larger than the sum of its proper divisors (19370314).

20640230 is a wasteful number, since it uses less digits than its factorization.

20640230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158791.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 20640230 is about 4543.1519895333. The cubic root of 20640230 is about 274.3078129155.

Adding to 20640230 its reverse (3204602), we get a palindrome (23844832).

The spelling of 20640230 in words is "twenty million, six hundred forty thousand, two hundred thirty".