821078646 has 16 divisors (see below), whose sum is σ = 1643189808. Its totient is φ = 273520800.

The previous prime is 821078639. The next prime is 821078659. The reversal of 821078646 is 646870128.

821078646 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 821078598 and 821078607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32485 + ... + 51936.

It is an arithmetic number, because the mean of its divisors is an integer number (102699363).

Almost surely, 2^821078646 is an apocalyptic number.

821078646 is an abundant number, since it is smaller than the sum of its proper divisors (822111162).

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

821078646 is a wasteful number, since it uses less digits than its factorization.

821078646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86047.

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 821078646 is about 28654.4699130869. The cubic root of 821078646 is about 936.4003898278.

The spelling of 821078646 in words is "eight hundred twenty-one million, seventy-eight thousand, six hundred forty-six".