869781921 has 8 divisors (see below), whose sum is σ = 1170548064. Its totient is φ = 574435200.

The previous prime is 869781907. The next prime is 869781923. The reversal of 869781921 is 129187968.

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

It is not a de Polignac number, because 869781921 - 2⁷ = 869781793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (869781923) 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 7 ways as a sum of consecutive naturals, for example, 1354480 + ... + 1355121.

It is an arithmetic number, because the mean of its divisors is an integer number (146318508).

Almost surely, 2^869781921 is an apocalyptic number.

It is an amenable number.

869781921 is a deficient number, since it is larger than the sum of its proper divisors (300766143).

869781921 is a wasteful number, since it uses less digits than its factorization.

869781921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2709711.

The product of its digits is 435456, while the sum is 51.

The square root of 869781921 is about 29492.0653905419. The cubic root of 869781921 is about 954.5604991379.

The spelling of 869781921 in words is "eight hundred sixty-nine million, seven hundred eighty-one thousand, nine hundred twenty-one".