21420404303 has 2 divisors, whose sum is σ = 21420404304. Its totient is φ = 21420404302.

The previous prime is 21420404297. The next prime is 21420404329. The reversal of 21420404303 is 30340402412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21420404303 - 2³⁴ = 4240535119 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21420400303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710202151 + 10710202152.

It is an arithmetic number, because the mean of its divisors is an integer number (10710202152).

Almost surely, 2^21420404303 is an apocalyptic number.

21420404303 is a deficient number, since it is larger than the sum of its proper divisors (1).

21420404303 is an equidigital number, since it uses as much as digits as its factorization.

21420404303 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 21420404303 its reverse (30340402412), we get a palindrome (51760806715).

The spelling of 21420404303 in words is "twenty-one billion, four hundred twenty million, four hundred four thousand, three hundred three".