999816949 has 2 divisors, whose sum is σ = 999816950. Its totient is φ = 999816948.

The previous prime is 999816943. The next prime is 999816973. The reversal of 999816949 is 949618999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 999697924 + 119025 = 31618^2 + 345^2 .

It is a cyclic number.

It is not a de Polignac number, because 999816949 - 2¹³ = 999808757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999816943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499908474 + 499908475.

It is an arithmetic number, because the mean of its divisors is an integer number (499908475).

Almost surely, 2^999816949 is an apocalyptic number.

It is an amenable number.

999816949 is a deficient number, since it is larger than the sum of its proper divisors (1).

999816949 is an equidigital number, since it uses as much as digits as its factorization.

999816949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11337408, while the sum is 64.

The square root of 999816949 is about 31619.8821787811. The cubic root of 999816949 is about 999.9389792765.

The spelling of 999816949 in words is "nine hundred ninety-nine million, eight hundred sixteen thousand, nine hundred forty-nine".