163221749 has 2 divisors, whose sum is σ = 163221750. Its totient is φ = 163221748.

The previous prime is 163221739. The next prime is 163221781. The reversal of 163221749 is 947122361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122988100 + 40233649 = 11090^2 + 6343^2 .

It is an emirp because it is prime and its reverse (947122361) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-163221749 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163221719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81610874 + 81610875.

It is an arithmetic number, because the mean of its divisors is an integer number (81610875).

Almost surely, 2^163221749 is an apocalyptic number.

It is an amenable number.

163221749 is a deficient number, since it is larger than the sum of its proper divisors (1).

163221749 is an equidigital number, since it uses as much as digits as its factorization.

163221749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 35.

The square root of 163221749 is about 12775.8267442855. The cubic root of 163221749 is about 546.5031578130.

The spelling of 163221749 in words is "one hundred sixty-three million, two hundred twenty-one thousand, seven hundred forty-nine".