3947512012181 has 2 divisors, whose sum is σ = 3947512012182. Its totient is φ = 3947512012180.

The previous prime is 3947512012159. The next prime is 3947512012189. The reversal of 3947512012181 is 1812102157493.

3947512012181 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., 3632325209956 + 315186802225 = 1905866^2 + 561415^2 .

It is an emirp because it is prime and its reverse (1812102157493) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3947512012181 - 2¹⁸ = 3947511750037 is a prime.

It is a super-2 number, since 2×3947512012181² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3947512012189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1973756006090 + 1973756006091.

It is an arithmetic number, because the mean of its divisors is an integer number (1973756006091).

Almost surely, 2^{3947512012181} is an apocalyptic number.

It is an amenable number.

3947512012181 is a deficient number, since it is larger than the sum of its proper divisors (1).

3947512012181 is an equidigital number, since it uses as much as digits as its factorization.

3947512012181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 44.

The spelling of 3947512012181 in words is "three trillion, nine hundred forty-seven billion, five hundred twelve million, twelve thousand, one hundred eighty-one".