991626983447 has 2 divisors, whose sum is σ = 991626983448. Its totient is φ = 991626983446.

The previous prime is 991626983393. The next prime is 991626983497. The reversal of 991626983447 is 744389626199.

It is a strong prime.

It is an emirp because it is prime and its reverse (744389626199) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 991626983447 - 2⁶ = 991626983383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991626983497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495813491723 + 495813491724.

It is an arithmetic number, because the mean of its divisors is an integer number (495813491724).

Almost surely, 2^991626983447 is an apocalyptic number.

991626983447 is a deficient number, since it is larger than the sum of its proper divisors (1).

991626983447 is an equidigital number, since it uses as much as digits as its factorization.

991626983447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141087744, while the sum is 68.

The spelling of 991626983447 in words is "nine hundred ninety-one billion, six hundred twenty-six million, nine hundred eighty-three thousand, four hundred forty-seven".