19644779852 has 48 divisors (see below), whose sum is σ = 36210954528. Its totient is φ = 9312929280.

The previous prime is 19644779851. The next prime is 19644779867. The reversal of 19644779852 is 25897744691.

It is not an unprimeable number, because it can be changed into a prime (19644779851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7929638 + ... + 7932114.

It is an arithmetic number, because the mean of its divisors is an integer number (754394886).

Almost surely, 2^19644779852 is an apocalyptic number.

It is an amenable number.

19644779852 is a deficient number, since it is larger than the sum of its proper divisors (16566174676).

19644779852 is a wasteful number, since it uses less digits than its factorization.

19644779852 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3866 (or 3864 counting only the distinct ones).

The product of its digits is 30481920, while the sum is 62.

The spelling of 19644779852 in words is "nineteen billion, six hundred forty-four million, seven hundred seventy-nine thousand, eight hundred fifty-two".