999694121 has 2 divisors, whose sum is σ = 999694122. Its totient is φ = 999694120.

The previous prime is 999694117. The next prime is 999694127. The reversal of 999694121 is 121496999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 512388496 + 487305625 = 22636^2 + 22075^2 .

It is a cyclic number.

It is not a de Polignac number, because 999694121 - 2² = 999694117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999694121.

It is not a weakly prime, because it can be changed into another prime (999694127) by changing a digit.

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, 499847060 + 499847061.

It is an arithmetic number, because the mean of its divisors is an integer number (499847061).

Almost surely, 2^999694121 is an apocalyptic number.

It is an amenable number.

999694121 is a deficient number, since it is larger than the sum of its proper divisors (1).

999694121 is an equidigital number, since it uses as much as digits as its factorization.

999694121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 50.

The square root of 999694121 is about 31617.9398601490. The cubic root of 999694121 is about 999.8980299358.

The spelling of 999694121 in words is "nine hundred ninety-nine million, six hundred ninety-four thousand, one hundred twenty-one".