1561556 has 6 divisors (see below), whose sum is σ = 2732730. Its totient is φ = 780776.

The previous prime is 1561541. The next prime is 1561559. The reversal of 1561556 is 6551651.

It can be written as a sum of positive squares in only one way, i.e., 839056 + 722500 = 916^2 + 850^2 .

It is a super-2 number, since 2×1561556² = 4876914282272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195191 + ... + 195198.

It is an arithmetic number, because the mean of its divisors is an integer number (455455).

2^1561556 is an apocalyptic number.

It is an amenable number.

1561556 is a deficient number, since it is larger than the sum of its proper divisors (1171174).

1561556 is a wasteful number, since it uses less digits than its factorization.

1561556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390393 (or 390391 counting only the distinct ones).

The product of its digits is 4500, while the sum is 29.

The square root of 1561556 is about 1249.6223429501. The cubic root of 1561556 is about 116.0163472800.

The spelling of 1561556 in words is "one million, five hundred sixty-one thousand, five hundred fifty-six".