999000421 has 2 divisors, whose sum is σ = 999000422. Its totient is φ = 999000420.

The previous prime is 999000341. The next prime is 999000433. The reversal of 999000421 is 124000999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 545736321 + 453264100 = 23361^2 + 21290^2 .

It is an emirp because it is prime and its reverse (124000999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999000421 - 2⁷ = 999000293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999000491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499500210 + 499500211.

It is an arithmetic number, because the mean of its divisors is an integer number (499500211).

Almost surely, 2^999000421 is an apocalyptic number.

It is an amenable number.

999000421 is a deficient number, since it is larger than the sum of its proper divisors (1).

999000421 is an equidigital number, since it uses as much as digits as its factorization.

999000421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 999000421 is about 31606.9679184828. The cubic root of 999000421 is about 999.6666959207. Note that the first 4 decimals are identical.

The spelling of 999000421 in words is "nine hundred ninety-nine million, four hundred twenty-one", and thus it is an aban number.