21636729318280 has 64 divisors (see below), whose sum is σ = 48937082342400. Its totient is φ = 8609574758400.

The previous prime is 21636729318137. The next prime is 21636729318313. The reversal of 21636729318280 is 8281392763612.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4087705 + ... + 7744855.

It is an arithmetic number, because the mean of its divisors is an integer number (764641911600).

Almost surely, 2^{21636729318280} is an apocalyptic number.

21636729318280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21636729318280 is an abundant number, since it is smaller than the sum of its proper divisors (27300353024120).

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

21636729318280 is a wasteful number, since it uses less digits than its factorization.

21636729318280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3657934 (or 3657930 counting only the distinct ones).

The product of its (nonzero) digits is 10450944, while the sum is 58.

The spelling of 21636729318280 in words is "twenty-one trillion, six hundred thirty-six billion, seven hundred twenty-nine million, three hundred eighteen thousand, two hundred eighty".