999981011 has 2 divisors, whose sum is σ = 999981012. Its totient is φ = 999981010.

The previous prime is 999980923. The next prime is 999981049. The reversal of 999981011 is 110189999.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (110189999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999981011 - 2²⁶ = 932872147 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (999981061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499990505 + 499990506.

It is an arithmetic number, because the mean of its divisors is an integer number (499990506).

Almost surely, 2^999981011 is an apocalyptic number.

999981011 is a deficient number, since it is larger than the sum of its proper divisors (1).

999981011 is an equidigital number, since it uses as much as digits as its factorization.

999981011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 47.

The square root of 999981011 is about 31622.4763578060. The cubic root of 999981011 is about 999.9936702933.

The spelling of 999981011 in words is "nine hundred ninety-nine million, nine hundred eighty-one thousand, eleven".