21420210433 has 2 divisors, whose sum is σ = 21420210434. Its totient is φ = 21420210432.

The previous prime is 21420210407. The next prime is 21420210439. The reversal of 21420210433 is 33401202412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19419258609 + 2000951824 = 139353^2 + 44732^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21420210433 is a prime.

It is not a weakly prime, because it can be changed into another prime (21420210439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710105216 + 10710105217.

It is an arithmetic number, because the mean of its divisors is an integer number (10710105217).

Almost surely, 2^21420210433 is an apocalyptic number.

It is an amenable number.

21420210433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21420210433 is an equidigital number, since it uses as much as digits as its factorization.

21420210433 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 21420210433 its reverse (33401202412), we get a palindrome (54821412845).

The spelling of 21420210433 in words is "twenty-one billion, four hundred twenty million, two hundred ten thousand, four hundred thirty-three".