165553822991 has 2 divisors, whose sum is σ = 165553822992. Its totient is φ = 165553822990.

The previous prime is 165553822981. The next prime is 165553823011. The reversal of 165553822991 is 199228355561.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165553822991 - 2¹⁸ = 165553560847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165553822921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82776911495 + 82776911496.

It is an arithmetic number, because the mean of its divisors is an integer number (82776911496).

Almost surely, 2^165553822991 is an apocalyptic number.

165553822991 is a deficient number, since it is larger than the sum of its proper divisors (1).

165553822991 is an equidigital number, since it uses as much as digits as its factorization.

165553822991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832000, while the sum is 56.

The spelling of 165553822991 in words is "one hundred sixty-five billion, five hundred fifty-three million, eight hundred twenty-two thousand, nine hundred ninety-one".