8661840 has 160 divisors (see below), whose sum is σ = 31176576. Its totient is φ = 1966080.

The previous prime is 8661839. The next prime is 8661841. The reversal of 8661840 is 481668.

It is an interprime number because it is at equal distance from previous prime (8661839) and next prime (8661841).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8661841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44784 + ... + 44976.

Almost surely, 2^8661840 is an apocalyptic number.

8661840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8661840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15588288).

8661840 is an abundant number, since it is smaller than the sum of its proper divisors (22514736).

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

8661840 is a wasteful number, since it uses less digits than its factorization.

8661840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 8661840 is about 2943.1004060344. The cubic root of 8661840 is about 205.3698656912.

The spelling of 8661840 in words is "eight million, six hundred sixty-one thousand, eight hundred forty".