1667005999 has 4 divisors (see below), whose sum is σ = 1679174064. Its totient is φ = 1654837936.

The previous prime is 1667005981. The next prime is 1667006023. The reversal of 1667005999 is 9995007661.

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 1667005999 - 2⁷ = 1667005871 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 (1667005099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6083827 + ... + 6084100.

It is an arithmetic number, because the mean of its divisors is an integer number (419793516).

Almost surely, 2^1667005999 is an apocalyptic number.

1667005999 is a deficient number, since it is larger than the sum of its proper divisors (12168065).

1667005999 is a wasteful number, since it uses less digits than its factorization.

1667005999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12168064.

The product of its (nonzero) digits is 918540, while the sum is 52.

The square root of 1667005999 is about 40828.9847902198. The cubic root of 1667005999 is about 1185.7115606301.

The spelling of 1667005999 in words is "one billion, six hundred sixty-seven million, five thousand, nine hundred ninety-nine".