21420210443 has 24 divisors (see below), whose sum is σ = 23962400640. Its totient is φ = 19078675200.

The previous prime is 21420210439. The next prime is 21420210491. The reversal of 21420210443 is 34401202412.

It is not a de Polignac number, because 21420210443 - 2² = 21420210439 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21420210433) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10978118 + ... + 10980068.

It is an arithmetic number, because the mean of its divisors is an integer number (998433360).

Almost surely, 2^21420210443 is an apocalyptic number.

21420210443 is a deficient number, since it is larger than the sum of its proper divisors (2542190197).

21420210443 is a wasteful number, since it uses less digits than its factorization.

21420210443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3795 (or 3776 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21420210443 its reverse (34401202412), we get a palindrome (55821412855).

The spelling of 21420210443 in words is "twenty-one billion, four hundred twenty million, two hundred ten thousand, four hundred forty-three".