21081996626880 has 2688 divisors, whose sum is σ = 87557339971584. Its totient is φ = 4265843097600.

The previous prime is 21081996626857. The next prime is 21081996626959. The reversal of 21081996626880 is 8862669918012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 165999973377 + ... + 165999973503.

It is an arithmetic number, because the mean of its divisors is an integer number (32573415168).

Almost surely, 2^{21081996626880} is an apocalyptic number.

21081996626880 is a gapful number since it is divisible by the number (20) 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 21081996626880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43778669985792).

21081996626880 is an abundant number, since it is smaller than the sum of its proper divisors (66475343344704).

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

21081996626880 is a wasteful number, since it uses less digits than its factorization.

21081996626880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363 (or 346 counting only the distinct ones).

The product of its (nonzero) digits is 35831808, while the sum is 66.

The spelling of 21081996626880 in words is "twenty-one trillion, eighty-one billion, nine hundred ninety-six million, six hundred twenty-six thousand, eight hundred eighty".