163940281 has 2 divisors, whose sum is σ = 163940282. Its totient is φ = 163940280.

The previous prime is 163940279. The next prime is 163940317. The reversal of 163940281 is 182049361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141991056 + 21949225 = 11916^2 + 4685^2 .

It is a cyclic number.

It is not a de Polignac number, because 163940281 - 2¹ = 163940279 is a prime.

It is a super-2 number, since 2×163940281² = 53752831468717922, which contains 22 as substring.

Together with 163940279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (163940201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81970140 + 81970141.

It is an arithmetic number, because the mean of its divisors is an integer number (81970141).

Almost surely, 2^163940281 is an apocalyptic number.

It is an amenable number.

163940281 is a deficient number, since it is larger than the sum of its proper divisors (1).

163940281 is an equidigital number, since it uses as much as digits as its factorization.

163940281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 163940281 is about 12803.9166273449. The cubic root of 163940281 is about 547.3039195540.

The spelling of 163940281 in words is "one hundred sixty-three million, nine hundred forty thousand, two hundred eighty-one".