194641921 has 2 divisors, whose sum is σ = 194641922. Its totient is φ = 194641920.

The previous prime is 194641919. The next prime is 194641933. The reversal of 194641921 is 129146491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166126321 + 28515600 = 12889^2 + 5340^2 .

It is an emirp because it is prime and its reverse (129146491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 194641921 - 2¹ = 194641919 is a prime.

Together with 194641919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (194641981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97320960 + 97320961.

It is an arithmetic number, because the mean of its divisors is an integer number (97320961).

It is a Proth number, since it is equal to 1485 ⋅ 2¹⁷ + 1 and 1485 < 2¹⁷.

Almost surely, 2^194641921 is an apocalyptic number.

It is an amenable number.

194641921 is a deficient number, since it is larger than the sum of its proper divisors (1).

194641921 is an equidigital number, since it uses as much as digits as its factorization.

194641921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 37.

The square root of 194641921 is about 13951.4128675199. The cubic root of 194641921 is about 579.5338317251.

The spelling of 194641921 in words is "one hundred ninety-four million, six hundred forty-one thousand, nine hundred twenty-one".