21673520843 has 8 divisors (see below), whose sum is σ = 23345481600. Its totient is φ = 20002241088.

The previous prime is 21673520833. The next prime is 21673520857. The reversal of 21673520843 is 34802537612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21673520843 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21673520843.

It is not an unprimeable number, because it can be changed into a prime (21673520833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103163 + ... + 232356.

It is an arithmetic number, because the mean of its divisors is an integer number (2918185200).

Almost surely, 2^21673520843 is an apocalyptic number.

21673520843 is a deficient number, since it is larger than the sum of its proper divisors (1671960757).

21673520843 is a wasteful number, since it uses less digits than its factorization.

21673520843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340501.

The product of its (nonzero) digits is 241920, while the sum is 41.

The spelling of 21673520843 in words is "twenty-one billion, six hundred seventy-three million, five hundred twenty thousand, eight hundred forty-three".