991365311 has 2 divisors, whose sum is σ = 991365312. Its totient is φ = 991365310.

The previous prime is 991365257. The next prime is 991365329. The reversal of 991365311 is 113563199.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 991365311 - 2²⁶ = 924256447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991361311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495682655 + 495682656.

It is an arithmetic number, because the mean of its divisors is an integer number (495682656).

Almost surely, 2^991365311 is an apocalyptic number.

991365311 is a deficient number, since it is larger than the sum of its proper divisors (1).

991365311 is an equidigital number, since it uses as much as digits as its factorization.

991365311 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21870, while the sum is 38.

The square root of 991365311 is about 31485.9541859541. The cubic root of 991365311 is about 997.1134461574.

The spelling of 991365311 in words is "nine hundred ninety-one million, three hundred sixty-five thousand, three hundred eleven".