21728119968 has 192 divisors, whose sum is σ = 68204384640. Its totient is φ = 6704640000.

The previous prime is 21728119957. The next prime is 21728119979. The reversal of 21728119968 is 86991182712.

It is a happy number.

21728119968 is a `hidden beast` number, since 217 + 281 + 1 + 99 + 68 = 666.

It is an interprime number because it is at equal distance from previous prime (21728119957) and next prime (21728119979).

It is a super-2 number, since 2×21728119968² (a number of 21 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 883843 + ... + 908093.

It is an arithmetic number, because the mean of its divisors is an integer number (355231170).

Almost surely, 2^21728119968 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 21728119968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34102192320).

21728119968 is an abundant number, since it is smaller than the sum of its proper divisors (46476264672).

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

21728119968 is a wasteful number, since it uses less digits than its factorization.

21728119968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24348 (or 24334 counting only the distinct ones).

The product of its digits is 870912, while the sum is 54.

The spelling of 21728119968 in words is "twenty-one billion, seven hundred twenty-eight million, one hundred nineteen thousand, nine hundred sixty-eight".