561405978774 has 48 divisors (see below), whose sum is σ = 1224620366112. Its totient is φ = 185870732544.

The previous prime is 561405978769. The next prime is 561405978779. The reversal of 561405978774 is 477879504165.

561405978774 is a `hidden beast` number, since 5 + 61 + 405 + 97 + 87 + 7 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (561405978769) and next prime (561405978779).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561405978779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1969287 + ... + 2236269.

It is an arithmetic number, because the mean of its divisors is an integer number (25512924294).

Almost surely, 2^561405978774 is an apocalyptic number.

561405978774 is an abundant number, since it is smaller than the sum of its proper divisors (663214387338).

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

561405978774 is a wasteful number, since it uses less digits than its factorization.

561405978774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267781 (or 267778 counting only the distinct ones).

The product of its (nonzero) digits is 59270400, while the sum is 63.

The spelling of 561405978774 in words is "five hundred sixty-one billion, four hundred five million, nine hundred seventy-eight thousand, seven hundred seventy-four".