840007999 has 4 divisors (see below), whose sum is σ = 841378936. Its totient is φ = 838637064.

The previous prime is 840007979. The next prime is 840008033. The reversal of 840007999 is 999700048.

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 840007999 - 2⁷ = 840007871 is a prime.

It is a super-3 number, since 3×840007999³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840007969) 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 3 ways as a sum of consecutive naturals, for example, 684549 + ... + 685774.

It is an arithmetic number, because the mean of its divisors is an integer number (210344734).

Almost surely, 2^840007999 is an apocalyptic number.

840007999 is a deficient number, since it is larger than the sum of its proper divisors (1370937).

840007999 is a wasteful number, since it uses less digits than its factorization.

840007999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1370936.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 840007999 is about 28982.8914879106. The cubic root of 840007999 is about 943.5417910406.

The spelling of 840007999 in words is "eight hundred forty million, seven thousand, nine hundred ninety-nine".