3941400778657 has 2 divisors, whose sum is σ = 3941400778658. Its totient is φ = 3941400778656.

The previous prime is 3941400778643. The next prime is 3941400778723. The reversal of 3941400778657 is 7568770041493.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2781420082081 + 1159980696576 = 1667759^2 + 1077024^2 .

It is an emirp because it is prime and its reverse (7568770041493) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3941400778657 - 2³⁵ = 3907041040289 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3941400778595 and 3941400778604.

It is not a weakly prime, because it can be changed into another prime (3941400775657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1970700389328 + 1970700389329.

It is an arithmetic number, because the mean of its divisors is an integer number (1970700389329).

Almost surely, 2^{3941400778657} is an apocalyptic number.

It is an amenable number.

3941400778657 is a deficient number, since it is larger than the sum of its proper divisors (1).

3941400778657 is an equidigital number, since it uses as much as digits as its factorization.

3941400778657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35562240, while the sum is 61.

The spelling of 3941400778657 in words is "three trillion, nine hundred forty-one billion, four hundred million, seven hundred seventy-eight thousand, six hundred fifty-seven".