20640460044 has 24 divisors (see below), whose sum is σ = 48820816240. Its totient is φ = 6785904384.

The previous prime is 20640460039. The next prime is 20640460051. The reversal of 20640460044 is 44006404602.

It is a junction number, because it is equal to n+sod(n) for n = 20640459993 and 20640460020.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11780209 + ... + 11781960.

Almost surely, 2^20640460044 is an apocalyptic number.

It is an amenable number.

20640460044 is an abundant number, since it is smaller than the sum of its proper divisors (28180356196).

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

20640460044 is a wasteful number, since it uses less digits than its factorization.

20640460044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23562249 (or 23562247 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 30.

Adding to 20640460044 its reverse (44006404602), we get a palindrome (64646864646).

The spelling of 20640460044 in words is "twenty billion, six hundred forty million, four hundred sixty thousand, forty-four".