1605120019 has 4 divisors (see below), whose sum is σ = 1689600040. Its totient is φ = 1520640000.

The previous prime is 1605120017. The next prime is 1605120037. The reversal of 1605120019 is 9100215061.

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

It is a cyclic number.

It is not a de Polignac number, because 1605120019 - 2¹ = 1605120017 is a prime.

It is a super-2 number, since 2×1605120019² = 5152820550789120722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1605119975 and 1605120002.

It is not an unprimeable number, because it can be changed into a prime (1605120017) 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, 42239982 + ... + 42240019.

It is an arithmetic number, because the mean of its divisors is an integer number (422400010).

Almost surely, 2^1605120019 is an apocalyptic number.

1605120019 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1605120019 is a deficient number, since it is larger than the sum of its proper divisors (84480021).

1605120019 is an equidigital number, since it uses as much as digits as its factorization.

1605120019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84480020.

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 1605120019 is about 40063.9491188774. The cubic root of 1605120019 is about 1170.8533524144.

The spelling of 1605120019 in words is "one billion, six hundred five million, one hundred twenty thousand, nineteen".