40720681 has 2 divisors, whose sum is σ = 40720682. Its totient is φ = 40720680.

The previous prime is 40720663. The next prime is 40720703. The reversal of 40720681 is 18602704.

40720681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37015056 + 3705625 = 6084^2 + 1925^2 .

It is a cyclic number.

It is not a de Polignac number, because 40720681 - 2¹¹ = 40718633 is a prime.

It is a super-2 number, since 2×40720681² = 3316347722207522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (40720601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20360340 + 20360341.

It is an arithmetic number, because the mean of its divisors is an integer number (20360341).

Almost surely, 2^40720681 is an apocalyptic number.

It is an amenable number.

40720681 is a deficient number, since it is larger than the sum of its proper divisors (1).

40720681 is an equidigital number, since it uses as much as digits as its factorization.

40720681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 40720681 is about 6381.2758128763. The cubic root of 40720681 is about 344.0368881706.

The spelling of 40720681 in words is "forty million, seven hundred twenty thousand, six hundred eighty-one".