3161857891 has 2 divisors, whose sum is σ = 3161857892. Its totient is φ = 3161857890.

The previous prime is 3161857889. The next prime is 3161857901. The reversal of 3161857891 is 1987581613.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3161857891 - 2¹ = 3161857889 is a prime.

Together with 3161857889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (3161857801) 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, 1580928945 + 1580928946.

It is an arithmetic number, because the mean of its divisors is an integer number (1580928946).

Almost surely, 2^3161857891 is an apocalyptic number.

3161857891 is a deficient number, since it is larger than the sum of its proper divisors (1).

3161857891 is an equidigital number, since it uses as much as digits as its factorization.

3161857891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 49.

The square root of 3161857891 is about 56230.4000608212. The cubic root of 3161857891 is about 1467.7343182186.

The spelling of 3161857891 in words is "three billion, one hundred sixty-one million, eight hundred fifty-seven thousand, eight hundred ninety-one".