43768405681 has 135 divisors (see below), whose sum is σ = 64004668155. Its totient is φ = 29824835040.

The previous prime is 43768405679. The next prime is 43768405697. The reversal of 43768405681 is 18650486734.

The square root of 43768405681 is 209209.

It is a perfect power (a square), and thus also a powerful number.

43768405681 is digitally balanced in base 2, because in such base 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., 6474616225 + 37293789456 = 80465^2 + 193116^2 .

It is not a de Polignac number, because 43768405681 - 2¹ = 43768405679 is a prime.

It is a super-2 number, since 2×43768405681² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (43768405081) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 2303600290 + ... + 2303600308.

It is an arithmetic number, because the mean of its divisors is an integer number (474108653).

Almost surely, 2^43768405681 is an apocalyptic number.

43768405681 is the 209209-th square number.

43768405681 is the 104605-th centered octagonal number.

It is an amenable number.

43768405681 is a deficient number, since it is larger than the sum of its proper divisors (20236262474).

43768405681 is an equidigital number, since it uses as much as digits as its factorization.

43768405681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 52.

The spelling of 43768405681 in words is "forty-three billion, seven hundred sixty-eight million, four hundred five thousand, six hundred eighty-one".