561633 has 4 divisors (see below), whose sum is σ = 748848. Its totient is φ = 374420.

The previous prime is 561607. The next prime is 561667. The reversal of 561633 is 336165.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 561633 - 2⁸ = 561377 is a prime.

It is a super-4 number, since 4×561633⁴ (a number of 24 digits) contains 4444 as substring.

It is a D-number.

It is a Curzon number.

561633 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (561733) 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, 93603 + ... + 93608.

It is an arithmetic number, because the mean of its divisors is an integer number (187212).

2⁵⁶¹⁶³³ is an apocalyptic number.

It is an amenable number.

561633 is a deficient number, since it is larger than the sum of its proper divisors (187215).

561633 is a wasteful number, since it uses less digits than its factorization.

561633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187214.

The product of its digits is 1620, while the sum is 24.

The square root of 561633 is about 749.4217771055. The cubic root of 561633 is about 82.5057479925.

Adding to 561633 its reverse (336165), we get a palindrome (897798).

The spelling of 561633 in words is "five hundred sixty-one thousand, six hundred thirty-three".