21585787206368 has 96 divisors (see below), whose sum is σ = 52988555531520. Its totient is φ = 8409212098560.

The previous prime is 21585787206337. The next prime is 21585787206499. The reversal of 21585787206368 is 86360278758512.

It is a super-3 number, since 3×21585787206368³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21585787206298 and 21585787206307.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24685823 + ... + 25545281.

It is an arithmetic number, because the mean of its divisors is an integer number (551964120120).

Almost surely, 2^{21585787206368} is an apocalyptic number.

21585787206368 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21585787206368 is an abundant number, since it is smaller than the sum of its proper divisors (31402768325152).

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

21585787206368 is a wasteful number, since it uses less digits than its factorization.

21585787206368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869680 (or 869672 counting only the distinct ones).

The product of its (nonzero) digits is 270950400, while the sum is 68.

The spelling of 21585787206368 in words is "twenty-one trillion, five hundred eighty-five billion, seven hundred eighty-seven million, two hundred six thousand, three hundred sixty-eight".