1605225109 has 4 divisors (see below), whose sum is σ = 1606335904. Its totient is φ = 1604114316.

The previous prime is 1605225079. The next prime is 1605225113. The reversal of 1605225109 is 9015225061.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1605225109 - 2⁵ = 1605225077 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 (1605285109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553227 + ... + 556120.

It is an arithmetic number, because the mean of its divisors is an integer number (401583976).

Almost surely, 2^1605225109 is an apocalyptic number.

It is an amenable number.

1605225109 is a deficient number, since it is larger than the sum of its proper divisors (1110795).

1605225109 is a wasteful number, since it uses less digits than its factorization.

1605225109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1110794.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 1605225109 is about 40065.2606256343. The cubic root of 1605225109 is about 1170.8789044587.

The spelling of 1605225109 in words is "one billion, six hundred five million, two hundred twenty-five thousand, one hundred nine".