1809827605 has 16 divisors (see below), whose sum is σ = 2209577328. Its totient is φ = 1422720000.

The previous prime is 1809827561. The next prime is 1809827609. The reversal of 1809827605 is 5067289081.

It can be written as a sum of positive squares in 8 ways, for example, as 986022801 + 823804804 = 31401^2 + 28702^2 .

It is not a de Polignac number, because 1809827605 - 2¹⁵ = 1809794837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809827609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 394525 + ... + 399085.

It is an arithmetic number, because the mean of its divisors is an integer number (138098583).

Almost surely, 2^1809827605 is an apocalyptic number.

It is an amenable number.

1809827605 is a deficient number, since it is larger than the sum of its proper divisors (399749723).

1809827605 is a wasteful number, since it uses less digits than its factorization.

1809827605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5928.

The product of its (nonzero) digits is 241920, while the sum is 46.

The square root of 1809827605 is about 42542.0686497495. The cubic root of 1809827605 is about 1218.6502148240.

The spelling of 1809827605 in words is "one billion, eight hundred nine million, eight hundred twenty-seven thousand, six hundred five".