168209826821 has 8 divisors (see below), whose sum is σ = 169459012800. Its totient is φ = 166961198880.

The previous prime is 168209826817. The next prime is 168209826887. The reversal of 168209826821 is 128628902861.

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

It is a cyclic number.

It is not a de Polignac number, because 168209826821 - 2² = 168209826817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168209822821) 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, 475616 + ... + 750086.

It is an arithmetic number, because the mean of its divisors is an integer number (21182376600).

Almost surely, 2^168209826821 is an apocalyptic number.

It is an amenable number.

168209826821 is a deficient number, since it is larger than the sum of its proper divisors (1249185979).

168209826821 is a wasteful number, since it uses less digits than its factorization.

168209826821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279019.

The product of its (nonzero) digits is 1327104, while the sum is 53.

The spelling of 168209826821 in words is "one hundred sixty-eight billion, two hundred nine million, eight hundred twenty-six thousand, eight hundred twenty-one".