8661240 has 144 divisors (see below), whose sum is σ = 32811480. Its totient is φ = 1975680.

The previous prime is 8661239. The next prime is 8661241. The reversal of 8661240 is 421668.

8661240 is a `hidden beast` number, since 8 + 6 + 612 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (8661239) and next prime (8661241).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8661241) 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, 17395 + ... + 17885.

Almost surely, 2^8661240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8661240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16405740).

8661240 is an abundant number, since it is smaller than the sum of its proper divisors (24150240).

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

8661240 is a wasteful number, since it uses less digits than its factorization.

8661240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522 (or 508 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 8661240 is about 2942.9984709476. The cubic root of 8661240 is about 205.3651236362.

The spelling of 8661240 in words is "eight million, six hundred sixty-one thousand, two hundred forty".