394129221 has 8 divisors (see below), whose sum is σ = 527997024. Its totient is φ = 261507120.

The previous prime is 394129199. The next prime is 394129247. The reversal of 394129221 is 122921493.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 394129221 - 2⁷ = 394129093 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394122221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 310686 + ... + 311951.

It is an arithmetic number, because the mean of its divisors is an integer number (65999628).

Almost surely, 2^394129221 is an apocalyptic number.

It is an amenable number.

394129221 is a deficient number, since it is larger than the sum of its proper divisors (133867803).

394129221 is a wasteful number, since it uses less digits than its factorization.

394129221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622851.

The product of its digits is 7776, while the sum is 33.

The square root of 394129221 is about 19852.6880043988. The cubic root of 394129221 is about 733.1838301062.

The spelling of 394129221 in words is "three hundred ninety-four million, one hundred twenty-nine thousand, two hundred twenty-one".