21676523843 has 4 divisors (see below), whose sum is σ = 23343948768. Its totient is φ = 20009098920.

The previous prime is 21676523809. The next prime is 21676523849. The reversal of 21676523843 is 34832567612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21676523843 - 2⁸ = 21676523587 is a prime.

It is a super-2 number, since 2×21676523843² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21676523849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 833712443 + ... + 833712468.

It is an arithmetic number, because the mean of its divisors is an integer number (5835987192).

Almost surely, 2^21676523843 is an apocalyptic number.

21676523843 is a deficient number, since it is larger than the sum of its proper divisors (1667424925).

21676523843 is a wasteful number, since it uses less digits than its factorization.

21676523843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1667424924.

The product of its digits is 1451520, while the sum is 47.

The spelling of 21676523843 in words is "twenty-one billion, six hundred seventy-six million, five hundred twenty-three thousand, eight hundred forty-three".