3121975891 has 2 divisors, whose sum is σ = 3121975892. Its totient is φ = 3121975890.

The previous prime is 3121975841. The next prime is 3121975903. The reversal of 3121975891 is 1985791213.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 3121975891 - 2¹¹ = 3121973843 is a prime.

It is not a weakly prime, because it can be changed into another prime (3121975841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1560987945 + 1560987946.

It is an arithmetic number, because the mean of its divisors is an integer number (1560987946).

Almost surely, 2^3121975891 is an apocalyptic number.

3121975891 is a deficient number, since it is larger than the sum of its proper divisors (1).

3121975891 is an equidigital number, since it uses as much as digits as its factorization.

3121975891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 136080, while the sum is 46.

The square root of 3121975891 is about 55874.6444373474. The cubic root of 3121975891 is about 1461.5371143199.

The spelling of 3121975891 in words is "three billion, one hundred twenty-one million, nine hundred seventy-five thousand, eight hundred ninety-one".