561618943 has 4 divisors (see below), whose sum is σ = 575317008. Its totient is φ = 547920880.

The previous prime is 561618923. The next prime is 561618947. The reversal of 561618943 is 349816165.

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

It is a cyclic number.

It is not a de Polignac number, because 561618943 - 2²¹ = 559521791 is a prime.

It is an alternating number because its digits alternate between odd and even.

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 561618943.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561618947) 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, 6848971 + ... + 6849052.

It is an arithmetic number, because the mean of its divisors is an integer number (143829252).

Almost surely, 2^561618943 is an apocalyptic number.

561618943 is a deficient number, since it is larger than the sum of its proper divisors (13698065).

561618943 is a wasteful number, since it uses less digits than its factorization.

561618943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13698064.

The product of its digits is 155520, while the sum is 43.

The square root of 561618943 is about 23698.5008597590. The cubic root of 561618943 is about 825.0505964684.

The spelling of 561618943 in words is "five hundred sixty-one million, six hundred eighteen thousand, nine hundred forty-three".