999543345999 has 128 divisors (see below), whose sum is σ = 1590455623680. Its totient is φ = 552383193600.

The previous prime is 999543345989. The next prime is 999543346031.

999543345999 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 999543345999 - 2⁵ = 999543345967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999543345949) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 254270064 + ... + 254273994.

It is an arithmetic number, because the mean of its divisors is an integer number (12425434560).

Almost surely, 2^999543345999 is an apocalyptic number.

999543345999 is a deficient number, since it is larger than the sum of its proper divisors (590912277681).

999543345999 is a wasteful number, since it uses less digits than its factorization.

999543345999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4221.

The product of its digits is 1913187600, while the sum is 78.

The spelling of 999543345999 in words is "nine hundred ninety-nine billion, five hundred forty-three million, three hundred forty-five thousand, nine hundred ninety-nine".