820755057 has 4 divisors (see below), whose sum is σ = 1094340080. Its totient is φ = 547170036.

The previous prime is 820755043. The next prime is 820755073. The reversal of 820755057 is 750557028.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 820755057 - 2⁷ = 820754929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820755157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136792507 + ... + 136792512.

It is an arithmetic number, because the mean of its divisors is an integer number (273585020).

Almost surely, 2^820755057 is an apocalyptic number.

It is an amenable number.

820755057 is a deficient number, since it is larger than the sum of its proper divisors (273585023).

820755057 is a wasteful number, since it uses less digits than its factorization.

820755057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273585022.

The product of its (nonzero) digits is 98000, while the sum is 39.

The square root of 820755057 is about 28648.8229601148. The cubic root of 820755057 is about 936.2773611421.

The spelling of 820755057 in words is "eight hundred twenty million, seven hundred fifty-five thousand, fifty-seven".