3191249921 has 2 divisors, whose sum is σ = 3191249922. Its totient is φ = 3191249920.

The previous prime is 3191249891. The next prime is 3191249923. The reversal of 3191249921 is 1299421913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2727450625 + 463799296 = 52225^2 + 21536^2 .

It is a cyclic number.

It is not a de Polignac number, because 3191249921 - 2⁶ = 3191249857 is a prime.

Together with 3191249923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3191249923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1595624960 + 1595624961.

It is an arithmetic number, because the mean of its divisors is an integer number (1595624961).

Almost surely, 2^3191249921 is an apocalyptic number.

It is an amenable number.

3191249921 is a deficient number, since it is larger than the sum of its proper divisors (1).

3191249921 is an equidigital number, since it uses as much as digits as its factorization.

3191249921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 41.

The square root of 3191249921 is about 56491.1490500946. The cubic root of 3191249921 is about 1472.2682247475.

The spelling of 3191249921 in words is "three billion, one hundred ninety-one million, two hundred forty-nine thousand, nine hundred twenty-one".