561990240 has 288 divisors, whose sum is σ = 2214051840. Its totient is φ = 127153152.

The previous prime is 561990223. The next prime is 561990269. The reversal of 561990240 is 42099165.

561990240 is a `hidden beast` number, since 561 + 9 + 90 + 2 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 561990195 and 561990204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1279941 + ... + 1280379.

It is an arithmetic number, because the mean of its divisors is an integer number (7687680).

Almost surely, 2^561990240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561990240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1107025920).

561990240 is an abundant number, since it is smaller than the sum of its proper divisors (1652061600).

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

561990240 is a wasteful number, since it uses less digits than its factorization.

561990240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594 (or 583 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 561990240 is about 23706.3333309898. Note that the first 5 decimals coincide. The cubic root of 561990240 is about 825.2323753127.

It can be divided in two parts, 5619 and 90240, that added together give a palindrome (95859).

The spelling of 561990240 in words is "five hundred sixty-one million, nine hundred ninety thousand, two hundred forty".