561278906 has 4 divisors (see below), whose sum is σ = 841918362. Its totient is φ = 280639452.

The previous prime is 561278891. The next prime is 561278911. The reversal of 561278906 is 609872165.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 496621225 + 64657681 = 22285^2 + 8041^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140319725 + ... + 140319728.

Almost surely, 2^561278906 is an apocalyptic number.

561278906 is a deficient number, since it is larger than the sum of its proper divisors (280639456).

561278906 is a wasteful number, since it uses less digits than its factorization.

561278906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280639455.

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 561278906 is about 23691.3255433291. The cubic root of 561278906 is about 824.8840515348.

The spelling of 561278906 in words is "five hundred sixty-one million, two hundred seventy-eight thousand, nine hundred six".