21002119968 has 96 divisors (see below), whose sum is σ = 56667933504. Its totient is φ = 6805804032.

The previous prime is 21002119967. The next prime is 21002119979. The reversal of 21002119968 is 86991120012.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (21002119967) 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 15 ways as a sum of consecutive naturals, for example, 7198446 + ... + 7201362.

It is an arithmetic number, because the mean of its divisors is an integer number (590290974).

Almost surely, 2^21002119968 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 21002119968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28333966752).

21002119968 is an abundant number, since it is smaller than the sum of its proper divisors (35665813536).

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

21002119968 is a wasteful number, since it uses less digits than its factorization.

21002119968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4994 (or 4986 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 39.

The spelling of 21002119968 in words is "twenty-one billion, two million, one hundred nineteen thousand, nine hundred sixty-eight".