1999605 has 16 divisors (see below), whose sum is σ = 3231360. Its totient is φ = 1055808.

The previous prime is 1999603. The next prime is 1999607. The reversal of 1999605 is 5069991.

It is an interprime number because it is at equal distance from previous prime (1999603) and next prime (1999607).

It is not a de Polignac number, because 1999605 - 2¹ = 1999603 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999603) 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, 1024 + ... + 2246.

It is an arithmetic number, because the mean of its divisors is an integer number (201960).

2^1999605 is an apocalyptic number.

1999605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1999605 is a deficient number, since it is larger than the sum of its proper divisors (1231755).

1999605 is a wasteful number, since it uses less digits than its factorization.

1999605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1340.

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 1999605 is about 1414.0739018877. The cubic root of 1999605 is about 125.9838099631.

The spelling of 1999605 in words is "one million, nine hundred ninety-nine thousand, six hundred five".