40646918561 has 2 divisors, whose sum is σ = 40646918562. Its totient is φ = 40646918560.

The previous prime is 40646918479. The next prime is 40646918593. The reversal of 40646918561 is 16581964604.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21398130961 + 19248787600 = 146281^2 + 138740^2 .

It is a cyclic number.

It is not a de Polignac number, because 40646918561 - 2¹⁸ = 40646656417 is a prime.

It is not a weakly prime, because it can be changed into another prime (40646918161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20323459280 + 20323459281.

It is an arithmetic number, because the mean of its divisors is an integer number (20323459281).

Almost surely, 2^40646918561 is an apocalyptic number.

It is an amenable number.

40646918561 is a deficient number, since it is larger than the sum of its proper divisors (1).

40646918561 is an equidigital number, since it uses as much as digits as its factorization.

40646918561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1244160, while the sum is 50.

The spelling of 40646918561 in words is "forty billion, six hundred forty-six million, nine hundred eighteen thousand, five hundred sixty-one".