561634 has 4 divisors (see below), whose sum is σ = 842454. Its totient is φ = 280816.

The previous prime is 561607. The next prime is 561667. The reversal of 561634 is 436165.

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

It can be written as a sum of positive squares in only one way, i.e., 363609 + 198025 = 603^2 + 445^2 .

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 561599 and 561608.

It is an unprimeable number.

561634 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, 140407 + ... + 140410.

2⁵⁶¹⁶³⁴ is an apocalyptic number.

561634 is a deficient number, since it is larger than the sum of its proper divisors (280820).

561634 is a wasteful number, since it uses less digits than its factorization.

561634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280819.

The product of its digits is 2160, while the sum is 25.

The square root of 561634 is about 749.4224442863. The cubic root of 561634 is about 82.5057969603.

Adding to 561634 its reverse (436165), we get a palindrome (997799).

The spelling of 561634 in words is "five hundred sixty-one thousand, six hundred thirty-four".