557781021 has 24 divisors (see below), whose sum is σ = 921945024. Its totient is φ = 318329280.

The previous prime is 557781019. The next prime is 557781023. The reversal of 557781021 is 120187755.

557781021 is a `hidden beast` number, since 5 + 577 + 81 + 0 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (557781019) and next prime (557781023).

It is not a de Polignac number, because 557781021 - 2¹ = 557781019 is a prime.

It is a super-2 number, since 2×557781021² = 622239334775604882, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (557781023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48826 + ... + 59156.

It is an arithmetic number, because the mean of its divisors is an integer number (38414376).

Almost surely, 2^557781021 is an apocalyptic number.

It is an amenable number.

557781021 is a deficient number, since it is larger than the sum of its proper divisors (364164003).

557781021 is a wasteful number, since it uses less digits than its factorization.

557781021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11201 (or 11198 counting only the distinct ones).

The product of its (nonzero) digits is 19600, while the sum is 36.

The square root of 557781021 is about 23617.3881070706. The cubic root of 557781021 is about 823.1669229188.

The spelling of 557781021 in words is "five hundred fifty-seven million, seven hundred eighty-one thousand, twenty-one".