172821869 has 8 divisors (see below), whose sum is σ = 194615040. Its totient is φ = 152042400.

The previous prime is 172821851. The next prime is 172821889. The reversal of 172821869 is 968128271.

172821869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 172821869 - 2¹⁶ = 172756333 is a prime.

It is a super-3 number, since 3×172821869³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172821809) 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, 253064 + ... + 253745.

It is an arithmetic number, because the mean of its divisors is an integer number (24326880).

Almost surely, 2^172821869 is an apocalyptic number.

It is an amenable number.

172821869 is a deficient number, since it is larger than the sum of its proper divisors (21793171).

172821869 is a wasteful number, since it uses less digits than its factorization.

172821869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 506851.

The product of its digits is 96768, while the sum is 44.

The square root of 172821869 is about 13146.1731694056. The cubic root of 172821869 is about 557.0141560114.

The spelling of 172821869 in words is "one hundred seventy-two million, eight hundred twenty-one thousand, eight hundred sixty-nine".