821086164 has 72 divisors (see below), whose sum is σ = 2153948160. Its totient is φ = 263414592.

The previous prime is 821086163. The next prime is 821086171. The reversal of 821086164 is 461680128.

821086164 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821086163) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 382077 + ... + 384219.

Almost surely, 2^821086164 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 821086164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1076974080).

821086164 is an abundant number, since it is smaller than the sum of its proper divisors (1332861996).

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

821086164 is a wasteful number, since it uses less digits than its factorization.

821086164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2549 (or 2544 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 821086164 is about 28654.6010965080. The cubic root of 821086164 is about 936.4032477906.

The spelling of 821086164 in words is "eight hundred twenty-one million, eighty-six thousand, one hundred sixty-four".