163820281 has 8 divisors (see below), whose sum is σ = 165942504. Its totient is φ = 161710080.

The previous prime is 163820273. The next prime is 163820303. The reversal of 163820281 is 182028361.

It can be written as a sum of positive squares in 4 ways, for example, as 73874025 + 89946256 = 8595^2 + 9484^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 163820281 - 2³ = 163820273 is a prime.

It is a super-2 number, since 2×163820281² = 53674168933837922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163820981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26221 + ... + 31861.

It is an arithmetic number, because the mean of its divisors is an integer number (20742813).

Almost surely, 2^163820281 is an apocalyptic number.

It is an amenable number.

163820281 is a deficient number, since it is larger than the sum of its proper divisors (2122223).

163820281 is a wasteful number, since it uses less digits than its factorization.

163820281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6011.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 163820281 is about 12799.2297033845. The cubic root of 163820281 is about 547.1703495716.

The spelling of 163820281 in words is "one hundred sixty-three million, eight hundred twenty thousand, two hundred eighty-one".