43684681 has 2 divisors, whose sum is σ = 43684682. Its totient is φ = 43684680.

The previous prime is 43684651. The next prime is 43684691. The reversal of 43684681 is 18648634.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31539456 + 12145225 = 5616^2 + 3485^2 .

It is a cyclic number.

It is not a de Polignac number, because 43684681 - 2⁵ = 43684649 is a prime.

It is a super-2 number, since 2×43684681² = 3816702708143522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (43684631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21842340 + 21842341.

It is an arithmetic number, because the mean of its divisors is an integer number (21842341).

Almost surely, 2^43684681 is an apocalyptic number.

It is an amenable number.

43684681 is a deficient number, since it is larger than the sum of its proper divisors (1).

43684681 is an equidigital number, since it uses as much as digits as its factorization.

43684681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 110592, while the sum is 40.

The square root of 43684681 is about 6609.4387810161. The cubic root of 43684681 is about 352.1894883045.

The spelling of 43684681 in words is "forty-three million, six hundred eighty-four thousand, six hundred eighty-one".