21043245351405 has 16 divisors (see below), whose sum is σ = 33670670929920. Its totient is φ = 11222571398208.

The previous prime is 21043245351397. The next prime is 21043245351419. The reversal of 21043245351405 is 50415354234012.

It is not a de Polignac number, because 21043245351405 - 2³ = 21043245351397 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30446190 + ... + 31129679.

It is an arithmetic number, because the mean of its divisors is an integer number (2104416933120).

Almost surely, 2^{21043245351405} is an apocalyptic number.

It is an amenable number.

21043245351405 is a deficient number, since it is larger than the sum of its proper divisors (12627425578515).

21043245351405 is a wasteful number, since it uses less digits than its factorization.

21043245351405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61598660.

The product of its (nonzero) digits is 288000, while the sum is 39.

Adding to 21043245351405 its reverse (50415354234012), we get a palindrome (71458599585417).

The spelling of 21043245351405 in words is "twenty-one trillion, forty-three billion, two hundred forty-five million, three hundred fifty-one thousand, four hundred five".