194221997 has 2 divisors, whose sum is σ = 194221998. Its totient is φ = 194221996.

The previous prime is 194221969. The next prime is 194222029. The reversal of 194221997 is 799122491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122633476 + 71588521 = 11074^2 + 8461^2 .

It is a cyclic number.

It is not a de Polignac number, because 194221997 - 2¹⁸ = 193959853 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (194221897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97110998 + 97110999.

It is an arithmetic number, because the mean of its divisors is an integer number (97110999).

Almost surely, 2^194221997 is an apocalyptic number.

It is an amenable number.

194221997 is a deficient number, since it is larger than the sum of its proper divisors (1).

194221997 is an equidigital number, since it uses as much as digits as its factorization.

194221997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 44.

The square root of 194221997 is about 13936.3552265289. The cubic root of 194221997 is about 579.1167660634.

The spelling of 194221997 in words is "one hundred ninety-four million, two hundred twenty-one thousand, nine hundred ninety-seven".