21043242405530 has 8 divisors (see below), whose sum is σ = 37877836329972. Its totient is φ = 8417296962208.

The previous prime is 21043242405511. The next prime is 21043242405533. The reversal of 21043242405530 is 3550424234012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20853077511289 + 190164894241 = 4566517^2 + 436079^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21043242405533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1052162120267 + ... + 1052162120286.

Almost surely, 2^{21043242405530} is an apocalyptic number.

21043242405530 is a deficient number, since it is larger than the sum of its proper divisors (16834593924442).

21043242405530 is a wasteful number, since it uses less digits than its factorization.

21043242405530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2104324240560.

The product of its (nonzero) digits is 115200, while the sum is 35.

Adding to 21043242405530 its reverse (3550424234012), we get a palindrome (24593666639542).

The spelling of 21043242405530 in words is "twenty-one trillion, forty-three billion, two hundred forty-two million, four hundred five thousand, five hundred thirty".