194406221 has 2 divisors, whose sum is σ = 194406222. Its totient is φ = 194406220.

The previous prime is 194406209. The next prime is 194406253. The reversal of 194406221 is 122604491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134884996 + 59521225 = 11614^2 + 7715^2 .

It is an emirp because it is prime and its reverse (122604491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 194406221 - 2¹⁸ = 194144077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (194403221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97203110 + 97203111.

It is an arithmetic number, because the mean of its divisors is an integer number (97203111).

Almost surely, 2^194406221 is an apocalyptic number.

It is an amenable number.

194406221 is a deficient number, since it is larger than the sum of its proper divisors (1).

194406221 is an equidigital number, since it uses as much as digits as its factorization.

194406221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 194406221 is about 13942.9631355749. The cubic root of 194406221 is about 579.2998100282.

The spelling of 194406221 in words is "one hundred ninety-four million, four hundred six thousand, two hundred twenty-one".