21259906976 has 96 divisors (see below), whose sum is σ = 52291008000. Its totient is φ = 8266003200.

The previous prime is 21259906973. The next prime is 21259906979. The reversal of 21259906976 is 67960995212.

It is an interprime number because it is at equal distance from previous prime (21259906973) and next prime (21259906979).

It is a Harshad number since it is a multiple of its sum of digits (56).

It is not an unprimeable number, because it can be changed into a prime (21259906973) 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, 1220891 + ... + 1238181.

It is an arithmetic number, because the mean of its divisors is an integer number (544698000).

Almost surely, 2^21259906976 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 21259906976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26145504000).

21259906976 is an abundant number, since it is smaller than the sum of its proper divisors (31031101024).

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

21259906976 is a wasteful number, since it uses less digits than its factorization.

21259906976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17818 (or 17810 counting only the distinct ones).

The product of its (nonzero) digits is 3674160, while the sum is 56.

The spelling of 21259906976 in words is "twenty-one billion, two hundred fifty-nine million, nine hundred six thousand, nine hundred seventy-six".