21000310320043 has 4 divisors (see below), whose sum is σ = 21000417699240. Its totient is φ = 21000202940848.

The previous prime is 21000310319993. The next prime is 21000310320137. The reversal of 21000310320043 is 34002301300012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21000310320043 - 2⁹ = 21000310319531 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21000310320043.

It is not an unprimeable number, because it can be changed into a prime (21000310320943) 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, 53395705 + ... + 53787562.

It is an arithmetic number, because the mean of its divisors is an integer number (5250104424810).

Almost surely, 2^{21000310320043} is an apocalyptic number.

21000310320043 is a deficient number, since it is larger than the sum of its proper divisors (107379197).

21000310320043 is a wasteful number, since it uses less digits than its factorization.

21000310320043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107379196.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21000310320043 its reverse (34002301300012), we get a palindrome (55002611620055).

The spelling of 21000310320043 in words is "twenty-one trillion, three hundred ten million, three hundred twenty thousand, forty-three".