163086821 has 4 divisors (see below), whose sum is σ = 164701644. Its totient is φ = 161472000.

The previous prime is 163086817. The next prime is 163086827. The reversal of 163086821 is 128680361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 128680361 = 17 ⋅7569433.

It can be written as a sum of positive squares in 2 ways, for example, as 145564225 + 17522596 = 12065^2 + 4186^2 .

It is a cyclic number.

It is not a de Polignac number, because 163086821 - 2² = 163086817 is a prime.

It is a super-2 number, since 2×163086821² = 53194622367772082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163086827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807260 + ... + 807461.

It is an arithmetic number, because the mean of its divisors is an integer number (41175411).

Almost surely, 2^163086821 is an apocalyptic number.

It is an amenable number.

163086821 is a deficient number, since it is larger than the sum of its proper divisors (1614823).

163086821 is a wasteful number, since it uses less digits than its factorization.

163086821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614822.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 163086821 is about 12770.5450549301. The cubic root of 163086821 is about 546.3525265264.

The spelling of 163086821 in words is "one hundred sixty-three million, eighty-six thousand, eight hundred twenty-one".