161968217 has 4 divisors (see below), whose sum is σ = 170492880. Its totient is φ = 153443556.

The previous prime is 161968189. The next prime is 161968241. The reversal of 161968217 is 712869161.

161968217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 161968217 - 2⁸ = 161967961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161968267) 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, 4262303 + ... + 4262340.

It is an arithmetic number, because the mean of its divisors is an integer number (42623220).

Almost surely, 2^161968217 is an apocalyptic number.

It is an amenable number.

161968217 is a deficient number, since it is larger than the sum of its proper divisors (8524663).

161968217 is an equidigital number, since it uses as much as digits as its factorization.

161968217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8524662.

The product of its digits is 36288, while the sum is 41.

The square root of 161968217 is about 12726.6734459559. The cubic root of 161968217 is about 545.1005251823.

The spelling of 161968217 in words is "one hundred sixty-one million, nine hundred sixty-eight thousand, two hundred seventeen".