1665128 has 8 divisors (see below), whose sum is σ = 3122130. Its totient is φ = 832560.

The previous prime is 1665121. The next prime is 1665137. The reversal of 1665128 is 8215661.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 996004 + 669124 = 998^2 + 818^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 1665128.

It is not an unprimeable number, because it can be changed into a prime (1665121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104063 + ... + 104078.

2^1665128 is an apocalyptic number.

It is an amenable number.

1665128 is a deficient number, since it is larger than the sum of its proper divisors (1457002).

1665128 is a wasteful number, since it uses less digits than its factorization.

1665128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208147 (or 208143 counting only the distinct ones).

The product of its digits is 2880, while the sum is 29.

The square root of 1665128 is about 1290.3983880957. The cubic root of 1665128 is about 118.5266130949.

The spelling of 1665128 in words is "one million, six hundred sixty-five thousand, one hundred twenty-eight".