999810397 has 2 divisors, whose sum is σ = 999810398. Its totient is φ = 999810396.

The previous prime is 999810347. The next prime is 999810403. The reversal of 999810397 is 793018999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 957221721 + 42588676 = 30939^2 + 6526^2 .

It is an emirp because it is prime and its reverse (793018999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999810397 - 2¹¹ = 999808349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999810347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499905198 + 499905199.

It is an arithmetic number, because the mean of its divisors is an integer number (499905199).

Almost surely, 2^999810397 is an apocalyptic number.

It is an amenable number.

999810397 is a deficient number, since it is larger than the sum of its proper divisors (1).

999810397 is an equidigital number, since it uses as much as digits as its factorization.

999810397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1102248, while the sum is 55.

The square root of 999810397 is about 31619.7785729122. The cubic root of 999810397 is about 999.9367950052.

The spelling of 999810397 in words is "nine hundred ninety-nine million, eight hundred ten thousand, three hundred ninety-seven".