991331741 has 2 divisors, whose sum is σ = 991331742. Its totient is φ = 991331740.

The previous prime is 991331699. The next prime is 991331753. The reversal of 991331741 is 147133199.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 843612025 + 147719716 = 29045^2 + 12154^2 .

It is an emirp because it is prime and its reverse (147133199) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991331741 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 991331695 and 991331704.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991331791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495665870 + 495665871.

It is an arithmetic number, because the mean of its divisors is an integer number (495665871).

Almost surely, 2^991331741 is an apocalyptic number.

It is an amenable number.

991331741 is a deficient number, since it is larger than the sum of its proper divisors (1).

991331741 is an equidigital number, since it uses as much as digits as its factorization.

991331741 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20412, while the sum is 38.

The square root of 991331741 is about 31485.4210865918. The cubic root of 991331741 is about 997.1021911484.

The spelling of 991331741 in words is "nine hundred ninety-one million, three hundred thirty-one thousand, seven hundred forty-one".