393694091 has 4 divisors (see below), whose sum is σ = 449936112. Its totient is φ = 337452072.

The previous prime is 393694087. The next prime is 393694127. The reversal of 393694091 is 190496393.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190496393 = 10301 ⋅18493.

It is a cyclic number.

It is not a de Polignac number, because 393694091 - 2² = 393694087 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (393694291) 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, 28121000 + ... + 28121013.

It is an arithmetic number, because the mean of its divisors is an integer number (112484028).

Almost surely, 2^393694091 is an apocalyptic number.

393694091 is a deficient number, since it is larger than the sum of its proper divisors (56242021).

393694091 is an equidigital number, since it uses as much as digits as its factorization.

393694091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56242020.

The product of its (nonzero) digits is 157464, while the sum is 44.

The square root of 393694091 is about 19841.7260085911. The cubic root of 393694091 is about 732.9139120682.

The spelling of 393694091 in words is "three hundred ninety-three million, six hundred ninety-four thousand, ninety-one".