394430420221 has 4 divisors (see below), whose sum is σ = 394431712092. Its totient is φ = 394429128352.

The previous prime is 394430420183. The next prime is 394430420291. The reversal of 394430420221 is 122024034493.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 111072225625 + 283358194596 = 333275^2 + 532314^2 .

It is a cyclic number.

It is not a de Polignac number, because 394430420221 - 2¹⁵ = 394430387453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394430420291) 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, 96465 + ... + 893401.

It is an arithmetic number, because the mean of its divisors is an integer number (98607928023).

Almost surely, 2^394430420221 is an apocalyptic number.

It is an amenable number.

394430420221 is a deficient number, since it is larger than the sum of its proper divisors (1291871).

394430420221 is an equidigital number, since it uses as much as digits as its factorization.

394430420221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1291870.

The product of its (nonzero) digits is 41472, while the sum is 34.

The spelling of 394430420221 in words is "three hundred ninety-four billion, four hundred thirty million, four hundred twenty thousand, two hundred twenty-one".