20644723388 has 24 divisors (see below), whose sum is σ = 36481866960. Its totient is φ = 10221448320.

The previous prime is 20644723367. The next prime is 20644723397. The reversal of 20644723388 is 88332744602.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 750803 + ... + 777813.

It is an arithmetic number, because the mean of its divisors is an integer number (1520077790).

Almost surely, 2^20644723388 is an apocalyptic number.

It is an amenable number.

20644723388 is a deficient number, since it is larger than the sum of its proper divisors (15837143572).

20644723388 is a wasteful number, since it uses less digits than its factorization.

20644723388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28877 (or 28875 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 47.

The spelling of 20644723388 in words is "twenty billion, six hundred forty-four million, seven hundred twenty-three thousand, three hundred eighty-eight".