819901 has 4 divisors (see below), whose sum is σ = 833404. Its totient is φ = 806400.

The previous prime is 819899. The next prime is 819911. The reversal of 819901 is 109918.

819901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 109918 = 2 ⋅54959.

It can be written as a sum of positive squares in 2 ways, for example, as 63001 + 756900 = 251^2 + 870^2 .

It is a cyclic number.

It is not a de Polignac number, because 819901 - 2¹ = 819899 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 819901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (819911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6660 + ... + 6781.

It is an arithmetic number, because the mean of its divisors is an integer number (208351).

2⁸¹⁹⁹⁰¹ is an apocalyptic number.

It is an amenable number.

819901 is a deficient number, since it is larger than the sum of its proper divisors (13503).

819901 is a wasteful number, since it uses less digits than its factorization.

819901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13502.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 819901 is about 905.4838485583. The cubic root of 819901 is about 93.5952492901.

The spelling of 819901 in words is "eight hundred nineteen thousand, nine hundred one".