3934781891 has 2 divisors, whose sum is σ = 3934781892. Its totient is φ = 3934781890.

The previous prime is 3934781867. The next prime is 3934781897. The reversal of 3934781891 is 1981874393.

It is a strong prime.

It is an emirp because it is prime and its reverse (1981874393) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3934781891 - 2¹⁴ = 3934765507 is a prime.

It is not a weakly prime, because it can be changed into another prime (3934781897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1967390945 + 1967390946.

It is an arithmetic number, because the mean of its divisors is an integer number (1967390946).

Almost surely, 2^3934781891 is an apocalyptic number.

3934781891 is a deficient number, since it is larger than the sum of its proper divisors (1).

3934781891 is an equidigital number, since it uses as much as digits as its factorization.

3934781891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 53.

The square root of 3934781891 is about 62727.8398400583. The cubic root of 3934781891 is about 1578.7264601348.

The spelling of 3934781891 in words is "three billion, nine hundred thirty-four million, seven hundred eighty-one thousand, eight hundred ninety-one".