999899399 has 2 divisors, whose sum is σ = 999899400. Its totient is φ = 999899398.

The previous prime is 999899333. The next prime is 999899429. The reversal of 999899399 is 993998999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999899399 - 2⁸ = 999899143 is a prime.

It is a super-2 number, since 2×999899399² = 1999597616241122402, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999899099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499949699 + 499949700.

It is an arithmetic number, because the mean of its divisors is an integer number (499949700).

Almost surely, 2^999899399 is an apocalyptic number.

999899399 is a deficient number, since it is larger than the sum of its proper divisors (1).

999899399 is an equidigital number, since it uses as much as digits as its factorization.

999899399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 114791256, while the sum is 74.

The square root of 999899399 is about 31621.1859202023. The cubic root of 999899399 is about 999.9664652088.

The spelling of 999899399 in words is "nine hundred ninety-nine million, eight hundred ninety-nine thousand, three hundred ninety-nine".