21533500332031 has 2 divisors, whose sum is σ = 21533500332032. Its totient is φ = 21533500332030.

The previous prime is 21533500332013. The next prime is 21533500332053. The reversal of 21533500332031 is 13023300533512.

Together with previous prime (21533500332013) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21533500332031 - 2²³ = 21533491943423 is a prime.

It is a super-2 number, since 2×21533500332031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21533500331984 and 21533500332002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21533500332731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766750166015 + 10766750166016.

It is an arithmetic number, because the mean of its divisors is an integer number (10766750166016).

Almost surely, 2^{21533500332031} is an apocalyptic number.

21533500332031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21533500332031 is an equidigital number, since it uses as much as digits as its factorization.

21533500332031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24300, while the sum is 31.

Adding to 21533500332031 its reverse (13023300533512), we get a palindrome (34556800865543).

The spelling of 21533500332031 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred million, three hundred thirty-two thousand, thirty-one".