999663506 has 4 divisors (see below), whose sum is σ = 1499495262. Its totient is φ = 499831752.

The previous prime is 999663493. The next prime is 999663571. The reversal of 999663506 is 605366999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 605366999 = 19 ⋅31861421.

It can be written as a sum of positive squares in only one way, i.e., 911134225 + 88529281 = 30185^2 + 9409^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 249915875 + ... + 249915878.

Almost surely, 2^999663506 is an apocalyptic number.

999663506 is a deficient number, since it is larger than the sum of its proper divisors (499831756).

999663506 is a wasteful number, since it uses less digits than its factorization.

999663506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499831755.

The product of its (nonzero) digits is 2361960, while the sum is 53.

The square root of 999663506 is about 31617.4557167398. The cubic root of 999663506 is about 999.8878227501.

The spelling of 999663506 in words is "nine hundred ninety-nine million, six hundred sixty-three thousand, five hundred six".