999966431 has 4 divisors (see below), whose sum is σ = 1000045512. Its totient is φ = 999887352.

The previous prime is 999966427. The next prime is 999966439. The reversal of 999966431 is 134669999.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 999966431 - 2² = 999966427 is a prime.

It is a super-2 number, since 2×999966431² = 1999865726253755522, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999966439) 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, 15836 + ... + 47441.

It is an arithmetic number, because the mean of its divisors is an integer number (250011378).

Almost surely, 2^999966431 is an apocalyptic number.

999966431 is a deficient number, since it is larger than the sum of its proper divisors (79081).

999966431 is a wasteful number, since it uses less digits than its factorization.

999966431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79080.

The product of its digits is 2834352, while the sum is 56.

The square root of 999966431 is about 31622.2458247355. The cubic root of 999966431 is about 999.9888102081.

It can be divided in two parts, 999 and 966431, that multiplied together give a palindrome (965464569).

The spelling of 999966431 in words is "nine hundred ninety-nine million, nine hundred sixty-six thousand, four hundred thirty-one".