21354311633 has 2 divisors, whose sum is σ = 21354311634. Its totient is φ = 21354311632.

The previous prime is 21354311621. The next prime is 21354311647. The reversal of 21354311633 is 33611345312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20201505424 + 1152806209 = 142132^2 + 33953^2 .

It is a cyclic number.

It is not a de Polignac number, because 21354311633 - 2⁶ = 21354311569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21354311633.

It is not a weakly prime, because it can be changed into another prime (21354341633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677155816 + 10677155817.

It is an arithmetic number, because the mean of its divisors is an integer number (10677155817).

Almost surely, 2^21354311633 is an apocalyptic number.

It is an amenable number.

21354311633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21354311633 is an equidigital number, since it uses as much as digits as its factorization.

21354311633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 32.

Adding to 21354311633 its reverse (33611345312), we get a palindrome (54965656945).

The spelling of 21354311633 in words is "twenty-one billion, three hundred fifty-four million, three hundred eleven thousand, six hundred thirty-three".