20718834356 has 144 divisors (see below), whose sum is σ = 42471475200. Its totient is φ = 8823386880.

The previous prime is 20718834349. The next prime is 20718834379. The reversal of 20718834356 is 65343881702.

It is a self number, because there is not a number n which added to its sum of digits gives 20718834356.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 105171650 + ... + 105171846.

It is an arithmetic number, because the mean of its divisors is an integer number (294940800).

Almost surely, 2^20718834356 is an apocalyptic number.

It is an amenable number.

20718834356 is an abundant number, since it is smaller than the sum of its proper divisors (21752640844).

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

20718834356 is a wasteful number, since it uses less digits than its factorization.

20718834356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438 (or 425 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 47.

The spelling of 20718834356 in words is "twenty billion, seven hundred eighteen million, eight hundred thirty-four thousand, three hundred fifty-six".