561988 has 12 divisors (see below), whose sum is σ = 1124032. Its totient is φ = 240840.

The previous prime is 561983. The next prime is 561997. The reversal of 561988 is 889165.

561988 is an admirable number.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (561983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10008 + ... + 10063.

2⁵⁶¹⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

561988 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561988 is a wasteful number, since it uses less digits than its factorization.

561988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20082 (or 20080 counting only the distinct ones).

The product of its digits is 17280, while the sum is 37.

The square root of 561988 is about 749.6585889590. The cubic root of 561988 is about 82.5231278898.

The spelling of 561988 in words is "five hundred sixty-one thousand, nine hundred eighty-eight".