21012835968 has 288 divisors, whose sum is σ = 63599627520. Its totient is φ = 6914419200.

The previous prime is 21012835967. The next prime is 21012835993. The reversal of 21012835968 is 86953821012.

21012835968 is a `hidden beast` number, since 210 + 1 + 28 + 359 + 68 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21012835967) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 110014753 + ... + 110014943.

It is an arithmetic number, because the mean of its divisors is an integer number (220832040).

Almost surely, 2^21012835968 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 21012835968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31799813760).

21012835968 is an abundant number, since it is smaller than the sum of its proper divisors (42586791552).

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

21012835968 is an frugal number, since it uses more digits than its factorization.

21012835968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360 (or 327 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 21012835968 in words is "twenty-one billion, twelve million, eight hundred thirty-five thousand, nine hundred sixty-eight".