2172352821 has 16 divisors (see below), whose sum is σ = 3063383040. Its totient is φ = 1365502320.

The previous prime is 2172352813. The next prime is 2172352873. The reversal of 2172352821 is 1282532712.

It is not a de Polignac number, because 2172352821 - 2³ = 2172352813 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172352811) 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 in 15 ways as a sum of consecutive naturals, for example, 78285 + ... + 102338.

It is an arithmetic number, because the mean of its divisors is an integer number (191461440).

Almost surely, 2^2172352821 is an apocalyptic number.

It is an amenable number.

2172352821 is a deficient number, since it is larger than the sum of its proper divisors (891030219).

2172352821 is a wasteful number, since it uses less digits than its factorization.

2172352821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180856.

The product of its digits is 13440, while the sum is 33.

The square root of 2172352821 is about 46608.5058868014. The cubic root of 2172352821 is about 1295.1203300977.

The spelling of 2172352821 in words is "two billion, one hundred seventy-two million, three hundred fifty-two thousand, eight hundred twenty-one".