163217681 has 4 divisors (see below), whose sum is σ = 178055664. Its totient is φ = 148379700.

The previous prime is 163217651. The next prime is 163217737. The reversal of 163217681 is 186712361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 186712361 = 11 ⋅16973851.

It is a cyclic number.

It is not a de Polignac number, because 163217681 - 2¹⁸ = 162955537 is a prime.

It is a super-2 number, since 2×163217681² = 53280022782035522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163217651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7418975 + ... + 7418996.

It is an arithmetic number, because the mean of its divisors is an integer number (44513916).

Almost surely, 2^163217681 is an apocalyptic number.

163217681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

163217681 is a deficient number, since it is larger than the sum of its proper divisors (14837983).

163217681 is a wasteful number, since it uses less digits than its factorization.

163217681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14837982.

The product of its digits is 12096, while the sum is 35.

The square root of 163217681 is about 12775.6675363755. The cubic root of 163217681 is about 546.4986175821.

The spelling of 163217681 in words is "one hundred sixty-three million, two hundred seventeen thousand, six hundred eighty-one".