819945541 has 2 divisors, whose sum is σ = 819945542. Its totient is φ = 819945540.

The previous prime is 819945527. The next prime is 819945569. The reversal of 819945541 is 145549918.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 456890625 + 363054916 = 21375^2 + 19054^2 .

It is a cyclic number.

It is not a de Polignac number, because 819945541 - 2⁵ = 819945509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 819945491 and 819945500.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (819945521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409972770 + 409972771.

It is an arithmetic number, because the mean of its divisors is an integer number (409972771).

Almost surely, 2^819945541 is an apocalyptic number.

It is an amenable number.

819945541 is a deficient number, since it is larger than the sum of its proper divisors (1).

819945541 is an equidigital number, since it uses as much as digits as its factorization.

819945541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 259200, while the sum is 46.

The square root of 819945541 is about 28634.6912153772. The cubic root of 819945541 is about 935.9694410878.

The spelling of 819945541 in words is "eight hundred nineteen million, nine hundred forty-five thousand, five hundred forty-one".