991722647359 has 2 divisors, whose sum is σ = 991722647360. Its totient is φ = 991722647358.

The previous prime is 991722647347. The next prime is 991722647393. The reversal of 991722647359 is 953746227199.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 991722647359 - 2⁷ = 991722647231 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 991722647359.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991722647329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495861323679 + 495861323680.

It is an arithmetic number, because the mean of its divisors is an integer number (495861323680).

Almost surely, 2^991722647359 is an apocalyptic number.

991722647359 is a deficient number, since it is larger than the sum of its proper divisors (1).

991722647359 is an equidigital number, since it uses as much as digits as its factorization.

991722647359 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51438240, while the sum is 64.

The spelling of 991722647359 in words is "nine hundred ninety-one billion, seven hundred twenty-two million, six hundred forty-seven thousand, three hundred fifty-nine".