21178790688 has 288 divisors, whose sum is σ = 63264801600. Its totient is φ = 6195087360.

The previous prime is 21178790687. The next prime is 21178790771. The reversal of 21178790688 is 88609787112.

It is a super-2 number, since 2×21178790688² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21178790687) 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, 54443998 + ... + 54444386.

It is an arithmetic number, because the mean of its divisors is an integer number (219669450).

Almost surely, 2^21178790688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21178790688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31632400800).

21178790688 is an abundant number, since it is smaller than the sum of its proper divisors (42086010912).

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

21178790688 is a wasteful number, since it uses less digits than its factorization.

21178790688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 57.

The spelling of 21178790688 in words is "twenty-one billion, one hundred seventy-eight million, seven hundred ninety thousand, six hundred eighty-eight".