821865072 has 80 divisors (see below), whose sum is σ = 2531980800. Its totient is φ = 224606976.

The previous prime is 821865047. The next prime is 821865089. The reversal of 821865072 is 270568128.

821865072 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 821865072.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45447 + ... + 60902.

It is an arithmetic number, because the mean of its divisors is an integer number (31649760).

Almost surely, 2^821865072 is an apocalyptic number.

It is an amenable number.

821865072 is an abundant number, since it is smaller than the sum of its proper divisors (1710115728).

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

821865072 is a wasteful number, since it uses less digits than its factorization.

821865072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106390 (or 106384 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 821865072 is about 28668.1891998780. The cubic root of 821865072 is about 936.6992546732.

The spelling of 821865072 in words is "eight hundred twenty-one million, eight hundred sixty-five thousand, seventy-two".