20644361644 has 12 divisors (see below), whose sum is σ = 36343967184. Its totient is φ = 10260371024.

The previous prime is 20644361641. The next prime is 20644361653. The reversal of 20644361644 is 44616344602.

It is a junction number, because it is equal to n+sod(n) for n = 20644361597 and 20644361606.

It is not an unprimeable number, because it can be changed into a prime (20644361641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15451699 + ... + 15453034.

It is an arithmetic number, because the mean of its divisors is an integer number (3028663932).

Almost surely, 2^20644361644 is an apocalyptic number.

It is an amenable number.

20644361644 is a deficient number, since it is larger than the sum of its proper divisors (15699605540).

20644361644 is a wasteful number, since it uses less digits than its factorization.

20644361644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30904904 (or 30904902 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 40.

The spelling of 20644361644 in words is "twenty billion, six hundred forty-four million, three hundred sixty-one thousand, six hundred forty-four".