21109078368 has 288 divisors, whose sum is σ = 72131544576. Its totient is φ = 5725108224.

The previous prime is 21109078301. The next prime is 21109078409. The reversal of 21109078368 is 86387090112.

21109078368 is a `hidden beast` number, since 211 + 0 + 9 + 0 + 78 + 368 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is an unprimeable number.

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, 6350755 + ... + 6354077.

It is an arithmetic number, because the mean of its divisors is an integer number (250456752).

Almost surely, 2^21109078368 is an apocalyptic number.

21109078368 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21109078368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36065772288).

21109078368 is an abundant number, since it is smaller than the sum of its proper divisors (51022466208).

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

21109078368 is a wasteful number, since it uses less digits than its factorization.

21109078368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3506 (or 3495 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 21109078368 in words is "twenty-one billion, one hundred nine million, seventy-eight thousand, three hundred sixty-eight".