40351781 has 2 divisors, whose sum is σ = 40351782. Its totient is φ = 40351780.

The previous prime is 40351777. The next prime is 40351807. The reversal of 40351781 is 18715304.

40351781 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., 33930625 + 6421156 = 5825^2 + 2534^2 .

It is a cyclic number.

It is not a de Polignac number, because 40351781 - 2² = 40351777 is a prime.

It is a super-2 number, since 2×40351781² = 3256532459743922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40351721) 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, 20175890 + 20175891.

It is an arithmetic number, because the mean of its divisors is an integer number (20175891).

Almost surely, 2^40351781 is an apocalyptic number.

It is an amenable number.

40351781 is a deficient number, since it is larger than the sum of its proper divisors (1).

40351781 is an equidigital number, since it uses as much as digits as its factorization.

40351781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 40351781 is about 6352.3051721403. The cubic root of 40351781 is about 342.9948263407.

The spelling of 40351781 in words is "forty million, three hundred fifty-one thousand, seven hundred eighty-one".