21033520043 has 4 divisors (see below), whose sum is σ = 21057341448. Its totient is φ = 21009698640.

The previous prime is 21033520037. The next prime is 21033520073. The reversal of 21033520043 is 34002533012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21033520043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21033520073) 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, 11909378 + ... + 11911143.

It is an arithmetic number, because the mean of its divisors is an integer number (5264335362).

Almost surely, 2^21033520043 is an apocalyptic number.

21033520043 is a deficient number, since it is larger than the sum of its proper divisors (23821405).

21033520043 is an equidigital number, since it uses as much as digits as its factorization.

21033520043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23821404.

The product of its (nonzero) digits is 2160, while the sum is 23.

The spelling of 21033520043 in words is "twenty-one billion, thirty-three million, five hundred twenty thousand, forty-three".