8657681 has 2 divisors, whose sum is σ = 8657682. Its totient is φ = 8657680.

The previous prime is 8657651. The next prime is 8657687. The reversal of 8657681 is 1867568.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5216656 + 3441025 = 2284^2 + 1855^2 .

It is a cyclic number.

It is not a de Polignac number, because 8657681 - 2²² = 4463377 is a prime.

It is a super-2 number, since 2×8657681² = 149910880595522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8657687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4328840 + 4328841.

It is an arithmetic number, because the mean of its divisors is an integer number (4328841).

Almost surely, 2^8657681 is an apocalyptic number.

It is an amenable number.

8657681 is a deficient number, since it is larger than the sum of its proper divisors (1).

8657681 is an equidigital number, since it uses as much as digits as its factorization.

8657681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 41.

The square root of 8657681 is about 2942.3937533920. The cubic root of 8657681 is about 205.3369908435.

The spelling of 8657681 in words is "eight million, six hundred fifty-seven thousand, six hundred eighty-one".