11721739128 has 32 divisors (see below), whose sum is σ = 31968380160. Its totient is φ = 3552042080.

The previous prime is 11721739121. The next prime is 11721739147. The reversal of 11721739128 is 82193712711.

It is a self number, because there is not a number n which added to its sum of digits gives 11721739128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11721739121) 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 7 ways as a sum of consecutive naturals, for example, 22200000 + ... + 22200527.

It is an arithmetic number, because the mean of its divisors is an integer number (999011880).

Almost surely, 2^11721739128 is an apocalyptic number.

It is an amenable number.

11721739128 is an abundant number, since it is smaller than the sum of its proper divisors (20246641032).

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

11721739128 is a wasteful number, since it uses less digits than its factorization.

11721739128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44400547 (or 44400543 counting only the distinct ones).

The product of its digits is 42336, while the sum is 42.

The spelling of 11721739128 in words is "eleven billion, seven hundred twenty-one million, seven hundred thirty-nine thousand, one hundred twenty-eight".