991922807 has 2 divisors, whose sum is σ = 991922808. Its totient is φ = 991922806.

The previous prime is 991922761. The next prime is 991922831. The reversal of 991922807 is 708229199.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 991922807 - 2⁸ = 991922551 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991922887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495961403 + 495961404.

It is an arithmetic number, because the mean of its divisors is an integer number (495961404).

Almost surely, 2^991922807 is an apocalyptic number.

991922807 is a deficient number, since it is larger than the sum of its proper divisors (1).

991922807 is an equidigital number, since it uses as much as digits as its factorization.

991922807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 47.

The square root of 991922807 is about 31494.8060321063. The cubic root of 991922807 is about 997.3003206233.

The spelling of 991922807 in words is "nine hundred ninety-one million, nine hundred twenty-two thousand, eight hundred seven".