561779 has 4 divisors (see below), whose sum is σ = 563784. Its totient is φ = 559776.

The previous prime is 561767. The next prime is 561787. The reversal of 561779 is 977165.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561079) 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, 497 + ... + 1170.

It is an arithmetic number, because the mean of its divisors is an integer number (140946).

2⁵⁶¹⁷⁷⁹ is an apocalyptic number.

561779 is a deficient number, since it is larger than the sum of its proper divisors (2005).

561779 is a wasteful number, since it uses less digits than its factorization.

561779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2004.

The product of its digits is 13230, while the sum is 35.

The square root of 561779 is about 749.5191792076. The cubic root of 561779 is about 82.5128966677.

The spelling of 561779 in words is "five hundred sixty-one thousand, seven hundred seventy-nine".