21533500200991 has 2 divisors, whose sum is σ = 21533500200992. Its totient is φ = 21533500200990.

The previous prime is 21533500200967. The next prime is 21533500201007. The reversal of 21533500200991 is 19900200533512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21533500200991 - 2¹⁷ = 21533500069919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21533506200991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766750100495 + 10766750100496.

It is an arithmetic number, because the mean of its divisors is an integer number (10766750100496).

Almost surely, 2^{21533500200991} is an apocalyptic number.

21533500200991 is a deficient number, since it is larger than the sum of its proper divisors (1).

21533500200991 is an equidigital number, since it uses as much as digits as its factorization.

21533500200991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72900, while the sum is 40.

The spelling of 21533500200991 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred million, two hundred thousand, nine hundred ninety-one".