20421211043 has 4 divisors (see below), whose sum is σ = 21309089808. Its totient is φ = 19533332280.

The previous prime is 20421211037. The next prime is 20421211081. The reversal of 20421211043 is 34011212402.

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 20421211043 - 2¹² = 20421206947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20421211003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 443939348 + ... + 443939393.

It is an arithmetic number, because the mean of its divisors is an integer number (5327272452).

Almost surely, 2^20421211043 is an apocalyptic number.

20421211043 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20421211043 is a deficient number, since it is larger than the sum of its proper divisors (887878765).

20421211043 is an equidigital number, since it uses as much as digits as its factorization.

20421211043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 887878764.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 20421211043 its reverse (34011212402), we get a palindrome (54432423445).

The spelling of 20421211043 in words is "twenty billion, four hundred twenty-one million, two hundred eleven thousand, forty-three".