21318240340224 has 243 divisors, whose sum is σ = 62956564299993. Its totient is φ = 6937719699456.

The previous prime is 21318240340157. The next prime is 21318240340279. The reversal of 21318240340224 is 42204304281312.

The square root of 21318240340224 is 4617168.

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

21318240340224 is a `hidden beast` number, since 2 + 1 + 3 + 1 + 8 + 240 + 3 + 402 + 2 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16955288582400 + 4362951757824 = 4117680^2 + 2088768^2 .

It is a super-3 number, since 3×21318240340224³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9529833634 + ... + 9529835870.

Almost surely, 2^{21318240340224} is an apocalyptic number.

21318240340224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

21318240340224 is the 4617168-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21318240340224

21318240340224 is an abundant number, since it is smaller than the sum of its proper divisors (41638323959769).

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

21318240340224 is an frugal number, since it uses more digits than its factorization.

21318240340224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4582 (or 2285 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 36.

Multiplying 21318240340224 by its sum of digits (36), we get a square (767456652248064 = 27703008²).

21318240340224 divided by its sum of digits (36) gives a square (592173342784 = 769528²).

The spelling of 21318240340224 in words is "twenty-one trillion, three hundred eighteen billion, two hundred forty million, three hundred forty thousand, two hundred twenty-four".