21188748168 has 240 divisors, whose sum is σ = 70481002800. Its totient is φ = 5734411200.

The previous prime is 21188748157. The next prime is 21188748169. The reversal of 21188748168 is 86184788112.

21188748168 is a `hidden beast` number, since 21 + 1 + 8 + 87 + 481 + 68 = 666.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21188748169) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 3281343 + ... + 3287793.

It is an arithmetic number, because the mean of its divisors is an integer number (293670845).

Almost surely, 2^21188748168 is an apocalyptic number.

21188748168 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 21188748168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35240501400).

21188748168 is an abundant number, since it is smaller than the sum of its proper divisors (49292254632).

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

21188748168 is a wasteful number, since it uses less digits than its factorization.

21188748168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6510 (or 6482 counting only the distinct ones).

The product of its digits is 1376256, while the sum is 54.

The spelling of 21188748168 in words is "twenty-one billion, one hundred eighty-eight million, seven hundred forty-eight thousand, one hundred sixty-eight".