561552778 has 8 divisors (see below), whose sum is σ = 843135300. Its totient is φ = 280507680.

The previous prime is 561552773. The next prime is 561552907. The reversal of 561552778 is 877255165.

It can be written as a sum of positive squares in 2 ways, for example, as 554461209 + 7091569 = 23547^2 + 2663^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (561552773) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131733 + ... + 135928.

Almost surely, 2^561552778 is an apocalyptic number.

561552778 is a deficient number, since it is larger than the sum of its proper divisors (281582522).

561552778 is a wasteful number, since it uses less digits than its factorization.

561552778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268712.

The product of its digits is 588000, while the sum is 46.

The square root of 561552778 is about 23697.1048442631. The cubic root of 561552778 is about 825.0181951298.

It can be divided in two parts, 561552 and 778, that added together give a triangular number (562330 = T₁₀₆₀).

The spelling of 561552778 in words is "five hundred sixty-one million, five hundred fifty-two thousand, seven hundred seventy-eight".