21276859968 has 504 divisors, whose sum is σ = 77279162688. Its totient is φ = 5547128832.

The previous prime is 21276859943. The next prime is 21276859973. The reversal of 21276859968 is 86995867212.

It is a tau number, because it is divible by the number of its divisors (504).

It is a super-2 number, since 2×21276859968² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 37791655 + ... + 37792217.

It is an arithmetic number, because the mean of its divisors is an integer number (153331672).

Almost surely, 2^21276859968 is an apocalyptic number.

21276859968 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 21276859968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38639581344).

21276859968 is an abundant number, since it is smaller than the sum of its proper divisors (56002302720).

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

21276859968 is a wasteful number, since it uses less digits than its factorization.

21276859968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 711 (or 691 counting only the distinct ones).

The product of its digits is 26127360, while the sum is 63.

The spelling of 21276859968 in words is "twenty-one billion, two hundred seventy-six million, eight hundred fifty-nine thousand, nine hundred sixty-eight".