40728109 has 2 divisors, whose sum is σ = 40728110. Its totient is φ = 40728108.

The previous prime is 40728097. The next prime is 40728131. The reversal of 40728109 is 90182704.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23794884 + 16933225 = 4878^2 + 4115^2 .

It is a cyclic number.

It is not a de Polignac number, because 40728109 - 2¹¹ = 40726061 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40728139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20364054 + 20364055.

It is an arithmetic number, because the mean of its divisors is an integer number (20364055).

Almost surely, 2^40728109 is an apocalyptic number.

It is an amenable number.

40728109 is a deficient number, since it is larger than the sum of its proper divisors (1).

40728109 is an equidigital number, since it uses as much as digits as its factorization.

40728109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 40728109 is about 6381.8578016123. The cubic root of 40728109 is about 344.0578058843.

The spelling of 40728109 in words is "forty million, seven hundred twenty-eight thousand, one hundred nine".