819729121 has 8 divisors (see below), whose sum is σ = 832440224. Its totient is φ = 807032160.

The previous prime is 819729101. The next prime is 819729133. The reversal of 819729121 is 121927918.

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 819729121 - 2⁵ = 819729089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (819729101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 221341 + ... + 225013.

It is an arithmetic number, because the mean of its divisors is an integer number (104055028).

Almost surely, 2^819729121 is an apocalyptic number.

It is an amenable number.

819729121 is a deficient number, since it is larger than the sum of its proper divisors (12711103).

819729121 is a wasteful number, since it uses less digits than its factorization.

819729121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7071.

The product of its digits is 18144, while the sum is 40.

The square root of 819729121 is about 28630.9119833791. The cubic root of 819729121 is about 935.8870858903.

The spelling of 819729121 in words is "eight hundred nineteen million, seven hundred twenty-nine thousand, one hundred twenty-one".