561549518478 has 48 divisors (see below), whose sum is σ = 1343926706640. Its totient is φ = 172778358096.

The previous prime is 561549518477. The next prime is 561549518483. The reversal of 561549518478 is 874815945165.

561549518478 is a `hidden beast` number, since 5 + 6 + 1 + 5 + 49 + 518 + 4 + 78 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561549518473) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19840525 + ... + 19868807.

It is an arithmetic number, because the mean of its divisors is an integer number (27998473055).

Almost surely, 2^561549518478 is an apocalyptic number.

561549518478 is an abundant number, since it is smaller than the sum of its proper divisors (782377188162).

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

561549518478 is an frugal number, since it uses more digits than its factorization.

561549518478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56590 (or 28301 counting only the distinct ones).

The product of its digits is 48384000, while the sum is 63.

The spelling of 561549518478 in words is "five hundred sixty-one billion, five hundred forty-nine million, five hundred eighteen thousand, four hundred seventy-eight".