999143817 has 16 divisors (see below), whose sum is σ = 1523783040. Its totient is φ = 570460032.

The previous prime is 999143807. The next prime is 999143867. The reversal of 999143817 is 718341999.

It is a happy number.

It is not a de Polignac number, because 999143817 - 2⁷ = 999143689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999143817.

It is not an unprimeable number, because it can be changed into a prime (999143807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6453 + ... + 45165.

It is an arithmetic number, because the mean of its divisors is an integer number (95236440).

Almost surely, 2^999143817 is an apocalyptic number.

999143817 is the 25809-th pentagonal number.

It is an amenable number.

999143817 is a deficient number, since it is larger than the sum of its proper divisors (524639223).

999143817 is a wasteful number, since it uses less digits than its factorization.

999143817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39952.

The product of its digits is 489888, while the sum is 51.

The square root of 999143817 is about 31609.2362609412. The cubic root of 999143817 is about 999.7145241780.

The spelling of 999143817 in words is "nine hundred ninety-nine million, one hundred forty-three thousand, eight hundred seventeen".