21518582066352 has 2400 divisors, whose sum is σ = 81268614475776. Its totient is φ = 5492232345600.

The previous prime is 21518582066351. The next prime is 21518582066381. The reversal of 21518582066352 is 25366028581512.

21518582066352 is a `hidden beast` number, since 2 + 1 + 5 + 1 + 8 + 582 + 0 + 6 + 6 + 3 + 52 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21518582066351) by changing a digit.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 352763640402 + ... + 352763640462.

Almost surely, 2^{21518582066352} 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 21518582066352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40634307237888).

21518582066352 is an abundant number, since it is smaller than the sum of its proper divisors (59750032409424).

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

21518582066352 is an equidigital number, since it uses as much as digits as its factorization.

21518582066352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 6912000, while the sum is 54.

The spelling of 21518582066352 in words is "twenty-one trillion, five hundred eighteen billion, five hundred eighty-two million, sixty-six thousand, three hundred fifty-two".