20646020 has 24 divisors (see below), whose sum is σ = 44366784. Its totient is φ = 8066016.

The previous prime is 20646013. The next prime is 20646029. The reversal of 20646020 is 2064602.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 20645983 and 20646001.

It is not an unprimeable number, because it can be changed into a prime (20646029) 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, 11144 + ... + 12863.

It is an arithmetic number, because the mean of its divisors is an integer number (1848616).

Almost surely, 2^20646020 is an apocalyptic number.

20646020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20646020 is an abundant number, since it is smaller than the sum of its proper divisors (23720764).

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

20646020 is a wasteful number, since it uses less digits than its factorization.

20646020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24059 (or 24057 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 20646020 is about 4543.7891676441. The cubic root of 20646020 is about 274.3334601385. Note that the first 3 decimals are identical.

20646020 divided by its sum of digits (20) gives a palindrome (1032301).

The spelling of 20646020 in words is "twenty million, six hundred forty-six thousand, twenty".