821295864 has 24 divisors (see below), whose sum is σ = 2224343160. Its totient is φ = 273765264.

The previous prime is 821295833. The next prime is 821295869. The reversal of 821295864 is 468592128.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821295869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5703372 + ... + 5703515.

It is an arithmetic number, because the mean of its divisors is an integer number (92680965).

Almost surely, 2^821295864 is an apocalyptic number.

It is an amenable number.

821295864 is an abundant number, since it is smaller than the sum of its proper divisors (1403047296).

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

821295864 is a wasteful number, since it uses less digits than its factorization.

821295864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11406899 (or 11406892 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The square root of 821295864 is about 28658.2599611351. The cubic root of 821295864 is about 936.4829580798.

The spelling of 821295864 in words is "eight hundred twenty-one million, two hundred ninety-five thousand, eight hundred sixty-four".