168651643 has 4 divisors (see below), whose sum is σ = 169293168. Its totient is φ = 168010120.

The previous prime is 168651631. The next prime is 168651647. The reversal of 168651643 is 346156861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346156861 = 251 ⋅1379111.

It is a cyclic number.

It is not a de Polignac number, because 168651643 - 2¹⁷ = 168520571 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 168651596 and 168651605.

It is not an unprimeable number, because it can be changed into a prime (168651647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 320368 + ... + 320893.

It is an arithmetic number, because the mean of its divisors is an integer number (42323292).

Almost surely, 2^168651643 is an apocalyptic number.

168651643 is a deficient number, since it is larger than the sum of its proper divisors (641525).

168651643 is an equidigital number, since it uses as much as digits as its factorization.

168651643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641524.

The product of its digits is 103680, while the sum is 40.

The square root of 168651643 is about 12986.5947422717. The cubic root of 168651643 is about 552.4973408825.

The spelling of 168651643 in words is "one hundred sixty-eight million, six hundred fifty-one thousand, six hundred forty-three".