393147217 has 4 divisors (see below), whose sum is σ = 394128036. Its totient is φ = 392166400.

The previous prime is 393147197. The next prime is 393147241. The reversal of 393147217 is 712741393.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 300814336 + 92332881 = 17344^2 + 9609^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-393147217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (393147277) 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, 489808 + ... + 490609.

It is an arithmetic number, because the mean of its divisors is an integer number (98532009).

Almost surely, 2^393147217 is an apocalyptic number.

It is an amenable number.

393147217 is a deficient number, since it is larger than the sum of its proper divisors (980819).

393147217 is an equidigital number, since it uses as much as digits as its factorization.

393147217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980818.

The product of its digits is 31752, while the sum is 37.

The square root of 393147217 is about 19827.9403115906. The cubic root of 393147217 is about 732.5743952519.

The spelling of 393147217 in words is "three hundred ninety-three million, one hundred forty-seven thousand, two hundred seventeen".