856984129 has 4 divisors (see below), whose sum is σ = 869054400. Its totient is φ = 844913860.

The previous prime is 856984111. The next prime is 856984187. The reversal of 856984129 is 921489658.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 856984129 - 2¹⁹ = 856459841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856982129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6035029 + ... + 6035170.

It is an arithmetic number, because the mean of its divisors is an integer number (217263600).

Almost surely, 2^856984129 is an apocalyptic number.

It is an amenable number.

856984129 is a deficient number, since it is larger than the sum of its proper divisors (12070271).

856984129 is a wasteful number, since it uses less digits than its factorization.

856984129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12070270.

The product of its digits is 1244160, while the sum is 52.

The square root of 856984129 is about 29274.2912638376. The cubic root of 856984129 is about 949.8556120357.

The spelling of 856984129 in words is "eight hundred fifty-six million, nine hundred eighty-four thousand, one hundred twenty-nine".