820278563 has 4 divisors (see below), whose sum is σ = 883376928. Its totient is φ = 757180200.

The previous prime is 820278533. The next prime is 820278581. The reversal of 820278563 is 365872028.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 820278563 - 2¹² = 820274467 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 820278563.

It is not an unprimeable number, because it can be changed into a prime (820278523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31549163 + ... + 31549188.

It is an arithmetic number, because the mean of its divisors is an integer number (220844232).

Almost surely, 2^820278563 is an apocalyptic number.

820278563 is a deficient number, since it is larger than the sum of its proper divisors (63098365).

820278563 is a wasteful number, since it uses less digits than its factorization.

820278563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63098364.

The product of its (nonzero) digits is 161280, while the sum is 41.

The square root of 820278563 is about 28640.5056345030. The cubic root of 820278563 is about 936.0961390249.

The spelling of 820278563 in words is "eight hundred twenty million, two hundred seventy-eight thousand, five hundred sixty-three".