865772928 has 128 divisors (see below), whose sum is σ = 2594064000. Its totient is φ = 284207616.

The previous prime is 865772899. The next prime is 865772983. The reversal of 865772928 is 829277568.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 229683 + ... + 233421.

It is an arithmetic number, because the mean of its divisors is an integer number (20266125).

Almost surely, 2^865772928 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 865772928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1297032000).

865772928 is an abundant number, since it is smaller than the sum of its proper divisors (1728291072).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

865772928 is a wasteful number, since it uses less digits than its factorization.

865772928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3829 (or 3811 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The square root of 865772928 is about 29424.0195758499. The cubic root of 865772928 is about 953.0916554749.

The spelling of 865772928 in words is "eight hundred sixty-five million, seven hundred seventy-two thousand, nine hundred twenty-eight".