561345551 has 16 divisors (see below), whose sum is σ = 626373888. Its totient is φ = 499564800.

The previous prime is 561345541. The next prime is 561345569. The reversal of 561345551 is 155543165.

561345551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 561345551 - 2¹⁰ = 561344527 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 (561345541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110765 + ... + 115721.

It is an arithmetic number, because the mean of its divisors is an integer number (39148368).

Almost surely, 2^561345551 is an apocalyptic number.

561345551 is a deficient number, since it is larger than the sum of its proper divisors (65028337).

561345551 is a wasteful number, since it uses less digits than its factorization.

561345551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5282.

The product of its digits is 45000, while the sum is 35.

The square root of 561345551 is about 23692.7320290422. The cubic root of 561345551 is about 824.9166985375.

The spelling of 561345551 in words is "five hundred sixty-one million, three hundred forty-five thousand, five hundred fifty-one".