21009859678080 has 3840 divisors, whose sum is σ = 99380331388800. Its totient is φ = 4142013677568.

The previous prime is 21009859678051. The next prime is 21009859678111. The reversal of 21009859678080 is 8087695890012.

It is a happy number.

It is a super-2 number, since 2×21009859678080² (a number of 27 digits) contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 21009859677999 and 21009859678017.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 287806296924 + ... + 287806296996.

Almost surely, 2^{21009859678080} is an apocalyptic number.

21009859678080 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 21009859678080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49690165694400).

21009859678080 is an abundant number, since it is smaller than the sum of its proper divisors (78370471710720).

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

21009859678080 is an equidigital number, since it uses as much as digits as its factorization.

21009859678080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 63.

The spelling of 21009859678080 in words is "twenty-one trillion, nine billion, eight hundred fifty-nine million, six hundred seventy-eight thousand, eighty".