1664755 has 4 divisors (see below), whose sum is σ = 1997712. Its totient is φ = 1331800.

The previous prime is 1664713. The next prime is 1664771. The reversal of 1664755 is 5574661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5574661 = 653 ⋅8537.

It is not a de Polignac number, because 1664755 - 2⁷ = 1664627 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1664755.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166471 + ... + 166480.

It is an arithmetic number, because the mean of its divisors is an integer number (499428).

2^1664755 is an apocalyptic number.

1664755 is a deficient number, since it is larger than the sum of its proper divisors (332957).

1664755 is an equidigital number, since it uses as much as digits as its factorization.

1664755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332956.

The product of its digits is 25200, while the sum is 34.

The square root of 1664755 is about 1290.2538509921. The cubic root of 1664755 is about 118.5177621781.

It can be divided in two parts, 16 and 64755, that multiplied together give a triangular number (1036080 = T₁₄₃₉).

The spelling of 1664755 in words is "one million, six hundred sixty-four thousand, seven hundred fifty-five".