40651661 has 2 divisors, whose sum is σ = 40651662. Its totient is φ = 40651660.

The previous prime is 40651643. The next prime is 40651669. The reversal of 40651661 is 16615604.

40651661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37589161 + 3062500 = 6131^2 + 1750^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40651661 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40651669) 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, 20325830 + 20325831.

It is an arithmetic number, because the mean of its divisors is an integer number (20325831).

Almost surely, 2^40651661 is an apocalyptic number.

It is an amenable number.

40651661 is a deficient number, since it is larger than the sum of its proper divisors (1).

40651661 is an equidigital number, since it uses as much as digits as its factorization.

40651661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 40651661 is about 6375.8655098739. The cubic root of 40651661 is about 343.8424017823.

The spelling of 40651661 in words is "forty million, six hundred fifty-one thousand, six hundred sixty-one".