8661505 has 4 divisors (see below), whose sum is σ = 10393812. Its totient is φ = 6929200.

The previous prime is 8661491. The next prime is 8661509. The reversal of 8661505 is 5051668.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3073009 + 5588496 = 1753^2 + 2364^2 .

It is not a de Polignac number, because 8661505 - 2¹¹ = 8659457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8661509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 866146 + ... + 866155.

It is an arithmetic number, because the mean of its divisors is an integer number (2598453).

Almost surely, 2^8661505 is an apocalyptic number.

It is an amenable number.

8661505 is a deficient number, since it is larger than the sum of its proper divisors (1732307).

8661505 is a wasteful number, since it uses less digits than its factorization.

8661505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1732306.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 8661505 is about 2943.0434927129. The cubic root of 8661505 is about 205.3672180708.

The spelling of 8661505 in words is "eight million, six hundred sixty-one thousand, five hundred five".