331345891 has 2 divisors, whose sum is σ = 331345892. Its totient is φ = 331345890.

The previous prime is 331345867. The next prime is 331345897. The reversal of 331345891 is 198543133.

It is a strong prime.

It is an emirp because it is prime and its reverse (198543133) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-331345891 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 331345891.

It is not a weakly prime, because it can be changed into another prime (331345897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165672945 + 165672946.

It is an arithmetic number, because the mean of its divisors is an integer number (165672946).

Almost surely, 2^331345891 is an apocalyptic number.

331345891 is a deficient number, since it is larger than the sum of its proper divisors (1).

331345891 is an equidigital number, since it uses as much as digits as its factorization.

331345891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 37.

The square root of 331345891 is about 18202.9088609486. The cubic root of 331345891 is about 691.9805109673.

The spelling of 331345891 in words is "three hundred thirty-one million, three hundred forty-five thousand, eight hundred ninety-one".