999998261 has 2 divisors, whose sum is σ = 999998262. Its totient is φ = 999998260.

The previous prime is 999998243. The next prime is 999998269. The reversal of 999998261 is 162899999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 961372036 + 38626225 = 31006^2 + 6215^2 .

It is an emirp because it is prime and its reverse (162899999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999998261 - 2¹⁰ = 999997237 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 999998194 and 999998203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999998269) 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, 499999130 + 499999131.

It is an arithmetic number, because the mean of its divisors is an integer number (499999131).

Almost surely, 2^999998261 is an apocalyptic number.

It is an amenable number.

999998261 is a deficient number, since it is larger than the sum of its proper divisors (1).

999998261 is an equidigital number, since it uses as much as digits as its factorization.

999998261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5668704, while the sum is 62.

The square root of 999998261 is about 31622.7491056676. The cubic root of 999998261 is about 999.9994203330. Note that the first 3 decimals are identical.

The spelling of 999998261 in words is "nine hundred ninety-nine million, nine hundred ninety-eight thousand, two hundred sixty-one".