394921091 has 4 divisors (see below), whose sum is σ = 405594672. Its totient is φ = 384247512.

The previous prime is 394921081. The next prime is 394921103. The reversal of 394921091 is 190129493.

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

It is a cyclic number.

It is not a de Polignac number, because 394921091 - 2²⁶ = 327812227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394921001) 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, 5336735 + ... + 5336808.

It is an arithmetic number, because the mean of its divisors is an integer number (101398668).

Almost surely, 2^394921091 is an apocalyptic number.

394921091 is a deficient number, since it is larger than the sum of its proper divisors (10673581).

394921091 is a wasteful number, since it uses less digits than its factorization.

394921091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10673580.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 394921091 is about 19872.6216438597. The cubic root of 394921091 is about 733.6745303226.

The spelling of 394921091 in words is "three hundred ninety-four million, nine hundred twenty-one thousand, ninety-one".