561381556 has 6 divisors (see below), whose sum is σ = 982417730. Its totient is φ = 280690776.

The previous prime is 561381551. The next prime is 561381571. The reversal of 561381556 is 655183165.

It can be written as a sum of positive squares in only one way, i.e., 356605456 + 204776100 = 18884^2 + 14310^2 .

It is a super-2 number, since 2×561381556² = 630298502833962272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561381551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70172691 + ... + 70172698.

Almost surely, 2^561381556 is an apocalyptic number.

It is an amenable number.

561381556 is a deficient number, since it is larger than the sum of its proper divisors (421036174).

561381556 is a wasteful number, since it uses less digits than its factorization.

561381556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140345393 (or 140345391 counting only the distinct ones).

The product of its digits is 108000, while the sum is 40.

The square root of 561381556 is about 23693.4918490289. The cubic root of 561381556 is about 824.9343350246.

The spelling of 561381556 in words is "five hundred sixty-one million, three hundred eighty-one thousand, five hundred fifty-six".