21350018289664 has 351 divisors, whose sum is σ = 46328435959617. Its totient is φ = 9836793888768.

The previous prime is 21350018289661. The next prime is 21350018289667. The reversal of 21350018289664 is 46698281005312.

The square root of 21350018289664 is 4620608.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (21350018289661) and next prime (21350018289667).

It can be written as a sum of positive squares in only one way, i.e., 12119310438400 + 9230707851264 = 3481280^2 + 3038208^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21350018289661) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 292466003932 + ... + 292466004004.

Almost surely, 2^{21350018289664} is an apocalyptic number.

21350018289664 is the 4620608-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21350018289664

21350018289664 is an abundant number, since it is smaller than the sum of its proper divisors (24978417669953).

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

21350018289664 is an frugal number, since it uses more digits than its factorization.

21350018289664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 55.

The spelling of 21350018289664 in words is "twenty-one trillion, three hundred fifty billion, eighteen million, two hundred eighty-nine thousand, six hundred sixty-four".