19912644664836 has 144 divisors (see below), whose sum is σ = 62430476818752. Its totient is φ = 4867873382400.

The previous prime is 19912644664831. The next prime is 19912644664837. The reversal of 19912644664836 is 63846644621991.

It is a super-2 number, since 2×19912644664836² (a number of 27 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (69) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (19912644664831) 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 47 ways as a sum of consecutive naturals, for example, 90438285 + ... + 90658196.

It is an arithmetic number, because the mean of its divisors is an integer number (433544977908).

Almost surely, 2^{19912644664836} is an apocalyptic number.

It is an amenable number.

19912644664836 is an abundant number, since it is smaller than the sum of its proper divisors (42517832153916).

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

19912644664836 is a wasteful number, since it uses less digits than its factorization.

19912644664836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181096530 (or 181096521 counting only the distinct ones).

The product of its digits is 322486272, while the sum is 69.

The spelling of 19912644664836 in words is "nineteen trillion, nine hundred twelve billion, six hundred forty-four million, six hundred sixty-four thousand, eight hundred thirty-six".