556821773 has 4 divisors (see below), whose sum is σ = 557664828. Its totient is φ = 555978720.

The previous prime is 556821767. The next prime is 556821817. The reversal of 556821773 is 377128655.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 443228809 + 113592964 = 21053^2 + 10658^2 .

It is a cyclic number.

It is not a de Polignac number, because 556821773 - 2¹⁸ = 556559629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (556821673) 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, 420536 + ... + 421857.

It is an arithmetic number, because the mean of its divisors is an integer number (139416207).

Almost surely, 2^556821773 is an apocalyptic number.

It is an amenable number.

556821773 is a deficient number, since it is larger than the sum of its proper divisors (843055).

556821773 is an equidigital number, since it uses as much as digits as its factorization.

556821773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843054.

The product of its digits is 352800, while the sum is 44.

The square root of 556821773 is about 23597.0712801398. The cubic root of 556821773 is about 822.6947697021.

The spelling of 556821773 in words is "five hundred fifty-six million, eight hundred twenty-one thousand, seven hundred seventy-three".