21531355330319 has 2 divisors, whose sum is σ = 21531355330320. Its totient is φ = 21531355330318.

The previous prime is 21531355330193. The next prime is 21531355330343. The reversal of 21531355330319 is 91303355313512.

It is a happy number.

Together with previous prime (21531355330193) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21531355330319 is a prime.

It is a super-2 number, since 2×21531355330319² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21531355330319.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21531355530319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10765677665159 + 10765677665160.

It is an arithmetic number, because the mean of its divisors is an integer number (10765677665160).

Almost surely, 2^{21531355330319} is an apocalyptic number.

21531355330319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21531355330319 is an equidigital number, since it uses as much as digits as its factorization.

21531355330319 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 546750, while the sum is 44.

The spelling of 21531355330319 in words is "twenty-one trillion, five hundred thirty-one billion, three hundred fifty-five million, three hundred thirty thousand, three hundred nineteen".