561637 has 4 divisors (see below), whose sum is σ = 586080. Its totient is φ = 537196.

The previous prime is 561607. The next prime is 561667. The reversal of 561637 is 736165.

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 an interprime number because it is at equal distance from previous prime (561607) and next prime (561667).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561637 is a prime.

It is a super-2 number, since 2×561637² = 630872239538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561607) 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, 12187 + ... + 12232.

It is an arithmetic number, because the mean of its divisors is an integer number (146520).

2⁵⁶¹⁶³⁷ is an apocalyptic number.

It is an amenable number.

561637 is a deficient number, since it is larger than the sum of its proper divisors (24443).

561637 is a wasteful number, since it uses less digits than its factorization.

561637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24442.

The product of its digits is 3780, while the sum is 28.

The square root of 561637 is about 749.4244458249. The cubic root of 561637 is about 82.5059438632.

The spelling of 561637 in words is "five hundred sixty-one thousand, six hundred thirty-seven".