1605419509 has 4 divisors (see below), whose sum is σ = 1606219840. Its totient is φ = 1604619180.

The previous prime is 1605419507. The next prime is 1605419551. The reversal of 1605419509 is 9059145061.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9059145061 = 13477 ⋅672193.

It is a cyclic number.

It is not a de Polignac number, because 1605419509 - 2¹ = 1605419507 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 (1605419507) 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, 397149 + ... + 401170.

It is an arithmetic number, because the mean of its divisors is an integer number (401554960).

Almost surely, 2^1605419509 is an apocalyptic number.

It is an amenable number.

1605419509 is a deficient number, since it is larger than the sum of its proper divisors (800331).

1605419509 is an equidigital number, since it uses as much as digits as its factorization.

1605419509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800330.

The product of its (nonzero) digits is 48600, while the sum is 40.

The square root of 1605419509 is about 40067.6865940623. The cubic root of 1605419509 is about 1170.9261687894.

The spelling of 1605419509 in words is "one billion, six hundred five million, four hundred nineteen thousand, five hundred nine".