999910138 has 4 divisors (see below), whose sum is σ = 1499865210. Its totient is φ = 499955068.

The previous prime is 999910133. The next prime is 999910139. The reversal of 999910138 is 831019999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 831019999 = 5413 ⋅153523.

It can be written as a sum of positive squares in only one way, i.e., 997485889 + 2424249 = 31583^2 + 1557^2 .

It is a junction number, because it is equal to n+sod(n) for n = 999910091 and 999910100.

It is not an unprimeable number, because it can be changed into a prime (999910133) 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, 249977533 + ... + 249977536.

Almost surely, 2^999910138 is an apocalyptic number.

999910138 is a deficient number, since it is larger than the sum of its proper divisors (499955072).

999910138 is a wasteful number, since it uses less digits than its factorization.

999910138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499955071.

The product of its (nonzero) digits is 157464, while the sum is 49.

The square root of 999910138 is about 31621.3557267869. The cubic root of 999910138 is about 999.9700451027.

The spelling of 999910138 in words is "nine hundred ninety-nine million, nine hundred ten thousand, one hundred thirty-eight".