20640406206 has 32 divisors (see below), whose sum is σ = 47595587328. Its totient is φ = 5845069440.

The previous prime is 20640406183. The next prime is 20640406207. The reversal of 20640406206 is 60260404602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20640406207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2169760 + ... + 2179251.

It is an arithmetic number, because the mean of its divisors is an integer number (1487362104).

Almost surely, 2^20640406206 is an apocalyptic number.

20640406206 is an abundant number, since it is smaller than the sum of its proper divisors (26955181122).

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

20640406206 is a wasteful number, since it uses less digits than its factorization.

20640406206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4349136.

The product of its (nonzero) digits is 13824, while the sum is 30.

The spelling of 20640406206 in words is "twenty billion, six hundred forty million, four hundred six thousand, two hundred six".