1663667 has 4 divisors (see below), whose sum is σ = 1679040. Its totient is φ = 1648296.

The previous prime is 1663619. The next prime is 1663681. The reversal of 1663667 is 7663661.

It is a happy number.

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 1663667 - 2¹⁰ = 1662643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1663687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7523 + ... + 7740.

It is an arithmetic number, because the mean of its divisors is an integer number (419760).

2^1663667 is an apocalyptic number.

1663667 is a deficient number, since it is larger than the sum of its proper divisors (15373).

1663667 is a wasteful number, since it uses less digits than its factorization.

1663667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15372.

The product of its digits is 27216, while the sum is 35.

The square root of 1663667 is about 1289.8321596239. The cubic root of 1663667 is about 118.4919374718.

The spelling of 1663667 in words is "one million, six hundred sixty-three thousand, six hundred sixty-seven".