999842621 has 2 divisors, whose sum is σ = 999842622. Its totient is φ = 999842620.

The previous prime is 999842593. The next prime is 999842639. The reversal of 999842621 is 126248999.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 863536996 + 136305625 = 29386^2 + 11675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999842621 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999842621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999842671) 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, 499921310 + 499921311.

It is an arithmetic number, because the mean of its divisors is an integer number (499921311).

Almost surely, 2^999842621 is an apocalyptic number.

It is an amenable number.

999842621 is a deficient number, since it is larger than the sum of its proper divisors (1).

999842621 is an equidigital number, since it uses as much as digits as its factorization.

999842621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 50.

The square root of 999842621 is about 31620.2881232920. The cubic root of 999842621 is about 999.9475375811.

The spelling of 999842621 in words is "nine hundred ninety-nine million, eight hundred forty-two thousand, six hundred twenty-one".