21731536319 has 2 divisors, whose sum is σ = 21731536320. Its totient is φ = 21731536318.

The previous prime is 21731536297. The next prime is 21731536391. The reversal of 21731536319 is 91363513712.

Together with next prime (21731536391) 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 21731536319 - 2⁸ = 21731536063 is a prime.

It is a super-2 number, since 2×21731536319² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21731506319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10865768159 + 10865768160.

It is an arithmetic number, because the mean of its divisors is an integer number (10865768160).

Almost surely, 2^21731536319 is an apocalyptic number.

21731536319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21731536319 is an equidigital number, since it uses as much as digits as its factorization.

21731536319 is an evil number, because the sum of its binary digits is even.

The product of its digits is 102060, while the sum is 41.

The spelling of 21731536319 in words is "twenty-one billion, seven hundred thirty-one million, five hundred thirty-six thousand, three hundred nineteen".