8187561 has 10 divisors (see below), whose sum is σ = 12230922. Its totient is φ = 5458320.

The previous prime is 8187539. The next prime is 8187583. The reversal of 8187561 is 1657818.

It is an interprime number because it is at equal distance from previous prime (8187539) and next prime (8187583).

It can be written as a sum of positive squares in only one way, i.e., 8088336 + 99225 = 2844^2 + 315^2 .

It is not a de Polignac number, because 8187561 - 2¹⁹ = 7663273 is a prime.

It is an Ulam number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8187511) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 50460 + ... + 50621.

Almost surely, 2^8187561 is an apocalyptic number.

8187561 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

8187561 is a deficient number, since it is larger than the sum of its proper divisors (4043361).

8187561 is a wasteful number, since it uses less digits than its factorization.

8187561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101093 (or 101084 counting only the distinct ones).

The product of its digits is 13440, while the sum is 36.

The square root of 8187561 is about 2861.3914447345. The cubic root of 8187561 is about 201.5509500142.

The spelling of 8187561 in words is "eight million, one hundred eighty-seven thousand, five hundred sixty-one".