394537817 has 4 divisors (see below), whose sum is σ = 398157540. Its totient is φ = 390918096.

The previous prime is 394537807. The next prime is 394537849. The reversal of 394537817 is 718735493.

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 248031001 + 146506816 = 15749^2 + 12104^2 .

It is a cyclic number.

It is not a de Polignac number, because 394537817 - 2⁶ = 394537753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394537807) 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, 1809698 + ... + 1809915.

It is an arithmetic number, because the mean of its divisors is an integer number (99539385).

Almost surely, 2^394537817 is an apocalyptic number.

It is an amenable number.

394537817 is a deficient number, since it is larger than the sum of its proper divisors (3619723).

394537817 is a wasteful number, since it uses less digits than its factorization.

394537817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3619722.

The product of its digits is 635040, while the sum is 47.

The square root of 394537817 is about 19862.9760358311. The cubic root of 394537817 is about 733.4371078807.

The spelling of 394537817 in words is "three hundred ninety-four million, five hundred thirty-seven thousand, eight hundred seventeen".