21738362688 has 560 divisors, whose sum is σ = 79515004800. Its totient is φ = 5733089280.

The previous prime is 21738362687. The next prime is 21738362741. The reversal of 21738362688 is 88626383712.

21738362688 is a `hidden beast` number, since 2 + 1 + 7 + 3 + 8 + 3 + 626 + 8 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21738362687) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 28267968 + ... + 28268736.

It is an arithmetic number, because the mean of its divisors is an integer number (141991080).

Almost surely, 2^21738362688 is an apocalyptic number.

21738362688 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 21738362688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39757502400).

21738362688 is an abundant number, since it is smaller than the sum of its proper divisors (57776642112).

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

21738362688 is a wasteful number, since it uses less digits than its factorization.

21738362688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 860 (or 841 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

The spelling of 21738362688 in words is "twenty-one billion, seven hundred thirty-eight million, three hundred sixty-two thousand, six hundred eighty-eight".