561491713440 has 1440 divisors, whose sum is σ = 2434926823056. Its totient is φ = 117339586560.

The previous prime is 561491713421. The next prime is 561491713441. The reversal of 561491713440 is 44317194165.

561491713440 is a `hidden beast` number, since 5 + 61 + 491 + 71 + 34 + 4 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 93849097104 + 467642616336 = 306348^2 + 683844^2 .

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (561491713441) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 2409835564 + ... + 2409835796.

Almost surely, 2^561491713440 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 561491713440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1217463411528).

561491713440 is an abundant number, since it is smaller than the sum of its proper divisors (1873435109616).

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

561491713440 is a wasteful number, since it uses less digits than its factorization.

561491713440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340 (or 308 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 561491713440 in words is "five hundred sixty-one billion, four hundred ninety-one million, seven hundred thirteen thousand, four hundred forty".