21712570823 has 2 divisors, whose sum is σ = 21712570824. Its totient is φ = 21712570822.

The previous prime is 21712570787. The next prime is 21712570879. The reversal of 21712570823 is 32807521712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21712570823 - 2¹⁴ = 21712554439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21712570123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10856285411 + 10856285412.

It is an arithmetic number, because the mean of its divisors is an integer number (10856285412).

Almost surely, 2^21712570823 is an apocalyptic number.

21712570823 is a deficient number, since it is larger than the sum of its proper divisors (1).

21712570823 is an equidigital number, since it uses as much as digits as its factorization.

21712570823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47040, while the sum is 38.

The spelling of 21712570823 in words is "twenty-one billion, seven hundred twelve million, five hundred seventy thousand, eight hundred twenty-three".