194889521 has 2 divisors, whose sum is σ = 194889522. Its totient is φ = 194889520.

The previous prime is 194889481. The next prime is 194889577. The reversal of 194889521 is 125988491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 194881600 + 7921 = 13960^2 + 89^2 .

It is an emirp because it is prime and its reverse (125988491) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-194889521 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (194889421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97444760 + 97444761.

It is an arithmetic number, because the mean of its divisors is an integer number (97444761).

Almost surely, 2^194889521 is an apocalyptic number.

It is an amenable number.

194889521 is a deficient number, since it is larger than the sum of its proper divisors (1).

194889521 is an equidigital number, since it uses as much as digits as its factorization.

194889521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 47.

The square root of 194889521 is about 13960.2837005557. The cubic root of 194889521 is about 579.7794653041.

The spelling of 194889521 in words is "one hundred ninety-four million, eight hundred eighty-nine thousand, five hundred twenty-one".