1666545 has 8 divisors (see below), whose sum is σ = 2666496. Its totient is φ = 888816.

The previous prime is 1666541. The next prime is 1666559. The reversal of 1666545 is 5456661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1666545 - 2² = 1666541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666541) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 55537 + ... + 55566.

It is an arithmetic number, because the mean of its divisors is an integer number (333312).

2^1666545 is an apocalyptic number.

1666545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1666545 is a deficient number, since it is larger than the sum of its proper divisors (999951).

1666545 is a wasteful number, since it uses less digits than its factorization.

1666545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111111.

The product of its digits is 21600, while the sum is 33.

The square root of 1666545 is about 1290.9473265784. The cubic root of 1666545 is about 118.5602250438.

It can be divided in two parts, 1666 and 545, that added together give a triangular number (2211 = T₆₆).

The spelling of 1666545 in words is "one million, six hundred sixty-six thousand, five hundred forty-five".