999988919 has 2 divisors, whose sum is σ = 999988920. Its totient is φ = 999988918.

The previous prime is 999988903. The next prime is 999988949. The reversal of 999988919 is 919889999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 999988919 - 2⁴ = 999988903 is a prime.

It is a super-2 number, since 2×999988919² = 1999955676245577122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999988949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499994459 + 499994460.

It is an arithmetic number, because the mean of its divisors is an integer number (499994460).

Almost surely, 2^999988919 is an apocalyptic number.

999988919 is a deficient number, since it is larger than the sum of its proper divisors (1).

999988919 is an equidigital number, since it uses as much as digits as its factorization.

999988919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34012224, while the sum is 71.

The square root of 999988919 is about 31622.6013952047. The cubic root of 999988919 is about 999.9963063197.

The spelling of 999988919 in words is "nine hundred ninety-nine million, nine hundred eighty-eight thousand, nine hundred nineteen".