8681661 has 14 divisors (see below), whose sum is σ = 13017630. Its totient is φ = 5787288.

The previous prime is 8681639. The next prime is 8681663. The reversal of 8681661 is 1661868.

8681661 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 6859161 + 1822500 = 2619^2 + 1350^2 .

It is not a de Polignac number, because 8681661 - 2¹⁴ = 8665277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8681663) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 5226 + ... + 6683.

Almost surely, 2^8681661 is an apocalyptic number.

8681661 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

8681661 is a deficient number, since it is larger than the sum of its proper divisors (4335969).

8681661 is an equidigital number, since it uses as much as digits as its factorization.

8681661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11927 (or 11912 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 8681661 is about 2946.4658491148. The cubic root of 8681661 is about 205.5263965240.

The spelling of 8681661 in words is "eight million, six hundred eighty-one thousand, six hundred sixty-one".