21203435311 has 2 divisors, whose sum is σ = 21203435312. Its totient is φ = 21203435310.

The previous prime is 21203435299. The next prime is 21203435333. The reversal of 21203435311 is 11353430212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21203435311 - 2⁹ = 21203434799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21203435371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601717655 + 10601717656.

It is an arithmetic number, because the mean of its divisors is an integer number (10601717656).

Almost surely, 2^21203435311 is an apocalyptic number.

21203435311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203435311 is an equidigital number, since it uses as much as digits as its factorization.

21203435311 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 25.

Adding to 21203435311 its reverse (11353430212), we get a palindrome (32556865523).

The spelling of 21203435311 in words is "twenty-one billion, two hundred three million, four hundred thirty-five thousand, three hundred eleven".