21009676968 has 384 divisors, whose sum is σ = 74095257600. Its totient is φ = 5438036736.

The previous prime is 21009676957. The next prime is 21009676979. The reversal of 21009676968 is 86967690012.

It is an interprime number because it is at equal distance from previous prime (21009676957) and next prime (21009676979).

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 95 ways as a sum of consecutive naturals, for example, 5944930 + ... + 5948462.

It is an arithmetic number, because the mean of its divisors is an integer number (192956400).

Almost surely, 2^21009676968 is an apocalyptic number.

21009676968 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 21009676968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37047628800).

21009676968 is an abundant number, since it is smaller than the sum of its proper divisors (53085580632).

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

21009676968 is a wasteful number, since it uses less digits than its factorization.

21009676968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3603 (or 3587 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 21009676968 in words is "twenty-one billion, nine million, six hundred seventy-six thousand, nine hundred sixty-eight".