3957886346221 has 2 divisors, whose sum is σ = 3957886346222. Its totient is φ = 3957886346220.

The previous prime is 3957886346201. The next prime is 3957886346251. The reversal of 3957886346221 is 1226436887593.

3957886346221 is digitally balanced in base 3, 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., 2184820996996 + 1773065349225 = 1478114^2 + 1331565^2 .

It is a cyclic number.

It is not a de Polignac number, because 3957886346221 - 2²⁹ = 3957349475309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3957886346201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1978943173110 + 1978943173111.

It is an arithmetic number, because the mean of its divisors is an integer number (1978943173111).

Almost surely, 2^{3957886346221} is an apocalyptic number.

It is an amenable number.

3957886346221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3957886346221 is an equidigital number, since it uses as much as digits as its factorization.

3957886346221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104509440, while the sum is 64.

The spelling of 3957886346221 in words is "three trillion, nine hundred fifty-seven billion, eight hundred eighty-six million, three hundred forty-six thousand, two hundred twenty-one".