21707233531 has 2 divisors, whose sum is σ = 21707233532. Its totient is φ = 21707233530.

The previous prime is 21707233529. The next prime is 21707233553. The reversal of 21707233531 is 13533270712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21707233531 - 2¹ = 21707233529 is a prime.

It is a super-2 number, since 2×21707233531² (a number of 21 digits) contains 22 as substring.

Together with 21707233529, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21707233511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10853616765 + 10853616766.

It is an arithmetic number, because the mean of its divisors is an integer number (10853616766).

Almost surely, 2^21707233531 is an apocalyptic number.

21707233531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21707233531 is an equidigital number, since it uses as much as digits as its factorization.

21707233531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26460, while the sum is 34.

The spelling of 21707233531 in words is "twenty-one billion, seven hundred seven million, two hundred thirty-three thousand, five hundred thirty-one".