21201209933 has 2 divisors, whose sum is σ = 21201209934. Its totient is φ = 21201209932.

The previous prime is 21201209929. The next prime is 21201209957. The reversal of 21201209933 is 33990210212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21172287049 + 28922884 = 145507^2 + 5378^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201209933 - 2² = 21201209929 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21201209933.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201209963) 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, 10600604966 + 10600604967.

It is an arithmetic number, because the mean of its divisors is an integer number (10600604967).

Almost surely, 2^21201209933 is an apocalyptic number.

It is an amenable number.

21201209933 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201209933 is an equidigital number, since it uses as much as digits as its factorization.

21201209933 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 32.

The spelling of 21201209933 in words is "twenty-one billion, two hundred one million, two hundred nine thousand, nine hundred thirty-three".