561647940 has 192 divisors, whose sum is σ = 1860655104. Its totient is φ = 123927552.

The previous prime is 561647917. The next prime is 561647941. The reversal of 561647940 is 49746165.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 561647892 and 561647901.

It is not an unprimeable number, because it can be changed into a prime (561647941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2474107 + ... + 2474333.

It is an arithmetic number, because the mean of its divisors is an integer number (9690912).

Almost surely, 2^561647940 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 561647940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (930327552).

561647940 is an abundant number, since it is smaller than the sum of its proper divisors (1299007164).

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

561647940 is a wasteful number, since it uses less digits than its factorization.

561647940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 42.

The square root of 561647940 is about 23699.1126416159. The cubic root of 561647940 is about 825.0647956454.

The spelling of 561647940 in words is "five hundred sixty-one million, six hundred forty-seven thousand, nine hundred forty".