820877856 has 96 divisors (see below), whose sum is σ = 2251126080. Its totient is φ = 261651456.

The previous prime is 820877831. The next prime is 820877867. The reversal of 820877856 is 658778028.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 820877799 and 820877808.

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, 207610 + ... + 211526.

It is an arithmetic number, because the mean of its divisors is an integer number (23449230).

Almost surely, 2^820877856 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 820877856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1125563040).

820877856 is an abundant number, since it is smaller than the sum of its proper divisors (1430248224).

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

820877856 is a wasteful number, since it uses less digits than its factorization.

820877856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4026 (or 4018 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 51.

The square root of 820877856 is about 28650.9660570111. The cubic root of 820877856 is about 936.3240531847.

The spelling of 820877856 in words is "eight hundred twenty million, eight hundred seventy-seven thousand, eight hundred fifty-six".