56805478921 has 3 divisors (see below), whose sum is σ = 56805717261. Its totient is φ = 56805240582.

The previous prime is 56805478883. The next prime is 56805478949. The reversal of 56805478921 is 12987450865.

It is a happy number.

The square root of 56805478921 is 238339.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 56805478921 - 2¹⁵ = 56805446153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56805478981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 119170 + ... + 357508.

It is an arithmetic number, because the mean of its divisors is an integer number (18935239087).

Almost surely, 2^56805478921 is an apocalyptic number.

56805478921 is the 238339-th square number.

56805478921 is the 119170-th centered octagonal number.

It is an amenable number.

56805478921 is a deficient number, since it is larger than the sum of its proper divisors (238340).

56805478921 is an frugal number, since it uses more digits than its factorization.

56805478921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476678 (or 238339 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 55.

The spelling of 56805478921 in words is "fifty-six billion, eight hundred five million, four hundred seventy-eight thousand, nine hundred twenty-one".