561556553 has 4 divisors (see below), whose sum is σ = 561623748. Its totient is φ = 561489360.

The previous prime is 561556549. The next prime is 561556559. The reversal of 561556553 is 355655165.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 355655165 = 5 ⋅71131033.

It can be written as a sum of positive squares in 2 ways, for example, as 133356304 + 428200249 = 11548^2 + 20693^2 .

It is a cyclic number.

It is not a de Polignac number, because 561556553 - 2² = 561556549 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 561556553.

It is not an unprimeable number, because it can be changed into a prime (561556559) 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 3 ways as a sum of consecutive naturals, for example, 18926 + ... + 38487.

It is an arithmetic number, because the mean of its divisors is an integer number (140405937).

Almost surely, 2^561556553 is an apocalyptic number.

It is an amenable number.

561556553 is a deficient number, since it is larger than the sum of its proper divisors (67195).

561556553 is an equidigital number, since it uses as much as digits as its factorization.

561556553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67194.

The product of its digits is 337500, while the sum is 41.

The square root of 561556553 is about 23697.1844952096. The cubic root of 561556553 is about 825.0200438350.

The spelling of 561556553 in words is "five hundred sixty-one million, five hundred fifty-six thousand, five hundred fifty-three".