999906251 has 2 divisors, whose sum is σ = 999906252. Its totient is φ = 999906250.

The previous prime is 999906227. The next prime is 999906253. The reversal of 999906251 is 152609999.

It is a strong prime.

It is an emirp because it is prime and its reverse (152609999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999906251 - 2²⁶ = 932797387 is a prime.

Together with 999906253, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999906251.

It is not a weakly prime, because it can be changed into another prime (999906253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499953125 + 499953126.

It is an arithmetic number, because the mean of its divisors is an integer number (499953126).

Almost surely, 2^999906251 is an apocalyptic number.

999906251 is a deficient number, since it is larger than the sum of its proper divisors (1).

999906251 is an equidigital number, since it uses as much as digits as its factorization.

999906251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 393660, while the sum is 50.

The square root of 999906251 is about 31621.2942650993. The cubic root of 999906251 is about 999.9687493567.

The spelling of 999906251 in words is "nine hundred ninety-nine million, nine hundred six thousand, two hundred fifty-one".