1913809 has 4 divisors (see below), whose sum is σ = 2026404. Its totient is φ = 1801216.

The previous prime is 1913803. The next prime is 1913819. The reversal of 1913809 is 9083191.

1913809 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1373584 + 540225 = 1172^2 + 735^2 .

It is a cyclic number.

It is not a de Polignac number, because 1913809 - 2⁹ = 1913297 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1913803) 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, 56272 + ... + 56305.

It is an arithmetic number, because the mean of its divisors is an integer number (506601).

2^1913809 is an apocalyptic number.

It is an amenable number.

1913809 is a deficient number, since it is larger than the sum of its proper divisors (112595).

1913809 is a wasteful number, since it uses less digits than its factorization.

1913809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112594.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 1913809 is about 1383.4048575887. The cubic root of 1913809 is about 124.1555669752.

The spelling of 1913809 in words is "one million, nine hundred thirteen thousand, eight hundred nine".