561121280 has 96 divisors (see below), whose sum is σ = 1383684120. Its totient is φ = 218234880.

The previous prime is 561121277. The next prime is 561121291. The reversal of 561121280 is 82121165.

It can be written as a sum of positive squares in 4 ways, for example, as 520569856 + 40551424 = 22816^2 + 6368^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 378140 + ... + 379620.

Almost surely, 2^561121280 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 561121280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (691842060).

561121280 is an abundant number, since it is smaller than the sum of its proper divisors (822562840).

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

561121280 is a wasteful number, since it uses less digits than its factorization.

561121280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1545 (or 1525 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 561121280 is about 23687.9986491050. The cubic root of 561121280 is about 824.8068259073.

The spelling of 561121280 in words is "five hundred sixty-one million, one hundred twenty-one thousand, two hundred eighty".