20043505021 has 4 divisors (see below), whose sum is σ = 20044302012. Its totient is φ = 20042708032.

The previous prime is 20043504979. The next prime is 20043505051. The reversal of 20043505021 is 12050534002.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10930702500 + 9112802521 = 104550^2 + 95461^2 .

It is a cyclic number.

It is not a de Polignac number, because 20043505021 - 2¹³ = 20043496829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20043504983 and 20043505001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20043505051) 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, 359500 + ... + 411493.

It is an arithmetic number, because the mean of its divisors is an integer number (5011075503).

Almost surely, 2^20043505021 is an apocalyptic number.

It is an amenable number.

20043505021 is a deficient number, since it is larger than the sum of its proper divisors (796991).

20043505021 is an equidigital number, since it uses as much as digits as its factorization.

20043505021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796990.

The product of its (nonzero) digits is 1200, while the sum is 22.

The spelling of 20043505021 in words is "twenty billion, forty-three million, five hundred five thousand, twenty-one".