351666217 has 4 divisors (see below), whose sum is σ = 401904256. Its totient is φ = 301428180.

The previous prime is 351666191. The next prime is 351666239. The reversal of 351666217 is 712666153.

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: 712666153 = 983 ⋅724991.

It is a cyclic number.

It is not a de Polignac number, because 351666217 - 2⁷ = 351666089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (351666277) 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, 25119009 + ... + 25119022.

It is an arithmetic number, because the mean of its divisors is an integer number (100476064).

Almost surely, 2^351666217 is an apocalyptic number.

It is an amenable number.

351666217 is a deficient number, since it is larger than the sum of its proper divisors (50238039).

351666217 is an equidigital number, since it uses as much as digits as its factorization.

351666217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50238038.

The product of its digits is 45360, while the sum is 37.

The square root of 351666217 is about 18752.7655827081. The cubic root of 351666217 is about 705.8464203007.

The spelling of 351666217 in words is "three hundred fifty-one million, six hundred sixty-six thousand, two hundred seventeen".