18699138 has 72 divisors (see below), whose sum is σ = 44613504. Its totient is φ = 5646960.

The previous prime is 18699137. The next prime is 18699203. The reversal of 18699138 is 83199681.

It is a junction number, because it is equal to n+sod(n) for n = 18699093 and 18699102.

It is not an unprimeable number, because it can be changed into a prime (18699137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 397831 + ... + 397877.

It is an arithmetic number, because the mean of its divisors is an integer number (619632).

Almost surely, 2^18699138 is an apocalyptic number.

18699138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18699138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22306752).

18699138 is an abundant number, since it is smaller than the sum of its proper divisors (25914366).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18699138 is a wasteful number, since it uses less digits than its factorization.

18699138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140 (or 106 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 18699138 is about 4324.2499927733. The cubic root of 18699138 is about 265.4242072481.

The spelling of 18699138 in words is "eighteen million, six hundred ninety-nine thousand, one hundred thirty-eight".