8661906 has 72 divisors (see below), whose sum is σ = 21349692. Its totient is φ = 2534400.

The previous prime is 8661901. The next prime is 8661941. The reversal of 8661906 is 6091668.

It can be written as a sum of positive squares in 2 ways, for example, as 7868025 + 793881 = 2805^2 + 891^2 .

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (8661901) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 89250 + ... + 89346.

Almost surely, 2^8661906 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8661906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10674846).

8661906 is an abundant number, since it is smaller than the sum of its proper divisors (12687786).

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

8661906 is a wasteful number, since it uses less digits than its factorization.

8661906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 8661906 is about 2943.1116186784. Note that the first 3 decimals coincide. The cubic root of 8661906 is about 205.3703873039.

It can be divided in two parts, 866 and 1906, that added together give a palindrome (2772).

The spelling of 8661906 in words is "eight million, six hundred sixty-one thousand, nine hundred six".