40681637 has 2 divisors, whose sum is σ = 40681638. Its totient is φ = 40681636.

The previous prime is 40681591. The next prime is 40681639. The reversal of 40681637 is 73618604.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38328481 + 2353156 = 6191^2 + 1534^2 .

It is a cyclic number.

It is not a de Polignac number, because 40681637 - 2⁶ = 40681573 is a prime.

Together with 40681639, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 40681597 and 40681606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40681639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20340818 + 20340819.

It is an arithmetic number, because the mean of its divisors is an integer number (20340819).

Almost surely, 2^40681637 is an apocalyptic number.

It is an amenable number.

40681637 is a deficient number, since it is larger than the sum of its proper divisors (1).

40681637 is an equidigital number, since it uses as much as digits as its factorization.

40681637 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 40681637 is about 6378.2158163549. The cubic root of 40681637 is about 343.9268959719.

The spelling of 40681637 in words is "forty million, six hundred eighty-one thousand, six hundred thirty-seven".