8661555 has 48 divisors (see below), whose sum is σ = 17731584. Its totient is φ = 3827520.

The previous prime is 8661553. The next prime is 8661557. The reversal of 8661555 is 5551668.

It is an interprime number because it is at equal distance from previous prime (8661553) and next prime (8661557).

It is not a de Polignac number, because 8661555 - 2¹ = 8661553 is a prime.

8661555 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8661553) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9322 + ... + 10208.

It is an arithmetic number, because the mean of its divisors is an integer number (369408).

Almost surely, 2^8661555 is an apocalyptic number.

8661555 is an abundant number, since it is smaller than the sum of its proper divisors (9070029).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8661555 is a wasteful number, since it uses less digits than its factorization.

8661555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936 (or 933 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 8661555 is about 2943.0519873084. The cubic root of 8661555 is about 205.3676132424.

It can be divided in two parts, 8661 and 555, that added together give a square (9216 = 96²).

The spelling of 8661555 in words is "eight million, six hundred sixty-one thousand, five hundred fifty-five".