1664087 has 4 divisors (see below), whose sum is σ = 1673880. Its totient is φ = 1654296.

The previous prime is 1664083. The next prime is 1664101. The reversal of 1664087 is 7804661.

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 1664087 - 2² = 1664083 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664083) 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, 4637 + ... + 4982.

It is an arithmetic number, because the mean of its divisors is an integer number (418470).

2^1664087 is an apocalyptic number.

1664087 is a deficient number, since it is larger than the sum of its proper divisors (9793).

1664087 is an equidigital number, since it uses as much as digits as its factorization.

1664087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9792.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 1664087 is about 1289.9949612305. The cubic root of 1664087 is about 118.5019079019.

The spelling of 1664087 in words is "one million, six hundred sixty-four thousand, eighty-seven".