820911057 has 4 divisors (see below), whose sum is σ = 1094548080. Its totient is φ = 547274036.

The previous prime is 820911053. The next prime is 820911067. The reversal of 820911057 is 750119028.

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 a cyclic number.

It is not a de Polignac number, because 820911057 - 2² = 820911053 is a prime.

It is not an unprimeable number, because it can be changed into a prime (820911053) 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, 136818507 + ... + 136818512.

It is an arithmetic number, because the mean of its divisors is an integer number (273637020).

Almost surely, 2^820911057 is an apocalyptic number.

It is an amenable number.

820911057 is a deficient number, since it is larger than the sum of its proper divisors (273637023).

820911057 is a wasteful number, since it uses less digits than its factorization.

820911057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273637022.

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 820911057 is about 28651.5454556992. The cubic root of 820911057 is about 936.3366764495.

The spelling of 820911057 in words is "eight hundred twenty million, nine hundred eleven thousand, fifty-seven".