21533500201813 has 2 divisors, whose sum is σ = 21533500201814. Its totient is φ = 21533500201812.

The previous prime is 21533500201789. The next prime is 21533500201879. The reversal of 21533500201813 is 31810200533512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14755485816369 + 6778014385444 = 3841287^2 + 2603462^2 .

It is a cyclic number.

It is not a de Polignac number, because 21533500201813 - 2²¹ = 21533498104661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21533500201313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766750100906 + 10766750100907.

It is an arithmetic number, because the mean of its divisors is an integer number (10766750100907).

Almost surely, 2^{21533500201813} is an apocalyptic number.

It is an amenable number.

21533500201813 is a deficient number, since it is larger than the sum of its proper divisors (1).

21533500201813 is an equidigital number, since it uses as much as digits as its factorization.

21533500201813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 34.

The spelling of 21533500201813 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred million, two hundred one thousand, eight hundred thirteen".