561631680 has 168 divisors, whose sum is σ = 1943794944. Its totient is φ = 148838400.

The previous prime is 561631673. The next prime is 561631691. The reversal of 561631680 is 86136165.

It is a happy number.

561631680 is a `hidden beast` number, since 5 + 616 + 31 + 6 + 8 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 549570 + ... + 550590.

It is an arithmetic number, because the mean of its divisors is an integer number (11570208).

Almost surely, 2^561631680 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 561631680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (971897472).

561631680 is an abundant number, since it is smaller than the sum of its proper divisors (1382163264).

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

561631680 is a wasteful number, since it uses less digits than its factorization.

561631680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235 (or 1222 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 561631680 is about 23698.7695883141. The cubic root of 561631680 is about 825.0568335503.

The spelling of 561631680 in words is "five hundred sixty-one million, six hundred thirty-one thousand, six hundred eighty".