21000300043 has 4 divisors (see below), whose sum is σ = 21092004640. Its totient is φ = 20908595448.

The previous prime is 21000300007. The next prime is 21000300089. The reversal of 21000300043 is 34000300012.

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 21000300043 - 2¹⁷ = 21000168971 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000299996 and 21000300032.

It is not an unprimeable number, because it can be changed into a prime (21000300143) 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, 45851955 + ... + 45852412.

It is an arithmetic number, because the mean of its divisors is an integer number (5273001160).

Almost surely, 2^21000300043 is an apocalyptic number.

21000300043 is a deficient number, since it is larger than the sum of its proper divisors (91704597).

21000300043 is an equidigital number, since it uses as much as digits as its factorization.

21000300043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91704596.

The product of its (nonzero) digits is 72, while the sum is 13.

Adding to 21000300043 its reverse (34000300012), we get a palindrome (55000600055).

The spelling of 21000300043 in words is "twenty-one billion, three hundred thousand, forty-three".