194537813 has 2 divisors, whose sum is σ = 194537814. Its totient is φ = 194537812.

The previous prime is 194537779. The next prime is 194537821. The reversal of 194537813 is 318735491.

194537813 = 9862² + 9863².

194537813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 97278769 + 97259044 = 9863^2 + 9862^2 .

It is a cyclic number.

It is not a de Polignac number, because 194537813 - 2²⁶ = 127428949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (194537843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97268906 + 97268907.

It is an arithmetic number, because the mean of its divisors is an integer number (97268907).

Almost surely, 2^194537813 is an apocalyptic number.

194537813 is the 9863-rd centered square number.

It is an amenable number.

194537813 is a deficient number, since it is larger than the sum of its proper divisors (1).

194537813 is an equidigital number, since it uses as much as digits as its factorization.

194537813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 41.

The square root of 194537813 is about 13947.6812768288. The cubic root of 194537813 is about 579.4304883343.

The spelling of 194537813 in words is "one hundred ninety-four million, five hundred thirty-seven thousand, eight hundred thirteen".