561766 has 4 divisors (see below), whose sum is σ = 842652. Its totient is φ = 280882.

The previous prime is 561761. The next prime is 561767. The reversal of 561766 is 667165.

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

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561761) by changing a digit.

561766 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140440 + ... + 140443.

It is an arithmetic number, because the mean of its divisors is an integer number (210663).

2⁵⁶¹⁷⁶⁶ is an apocalyptic number.

561766 is a deficient number, since it is larger than the sum of its proper divisors (280886).

561766 is a wasteful number, since it uses less digits than its factorization.

561766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280885.

The product of its digits is 7560, while the sum is 31.

The square root of 561766 is about 749.5105069310. The cubic root of 561766 is about 82.5122601920.

The spelling of 561766 in words is "five hundred sixty-one thousand, seven hundred sixty-six".