561635 has 4 divisors (see below), whose sum is σ = 673968. Its totient is φ = 449304.

The previous prime is 561607. The next prime is 561667. The reversal of 561635 is 536165.

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-561635 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56159 + ... + 56168.

It is an arithmetic number, because the mean of its divisors is an integer number (168492).

2⁵⁶¹⁶³⁵ is an apocalyptic number.

561635 is a deficient number, since it is larger than the sum of its proper divisors (112333).

561635 is a wasteful number, since it uses less digits than its factorization.

561635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112332.

The product of its digits is 2700, while the sum is 26.

The square root of 561635 is about 749.4231114664. The cubic root of 561635 is about 82.5058459280.

The spelling of 561635 in words is "five hundred sixty-one thousand, six hundred thirty-five".