16509138 has 16 divisors (see below), whose sum is σ = 34756320. Its totient is φ = 5213376.

The previous prime is 16509131. The next prime is 16509139. The reversal of 16509138 is 83190561.

It is a junction number, because it is equal to n+sod(n) for n = 16509099 and 16509108.

It is not an unprimeable number, because it can be changed into a prime (16509131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72295 + ... + 72522.

It is an arithmetic number, because the mean of its divisors is an integer number (2172270).

Almost surely, 2^16509138 is an apocalyptic number.

16509138 is an abundant number, since it is smaller than the sum of its proper divisors (18247182).

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

16509138 is a wasteful number, since it uses less digits than its factorization.

16509138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144841.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 16509138 is about 4063.1438566706. The cubic root of 16509138 is about 254.6291572209.

Adding to 16509138 its reverse (83190561), we get a palindrome (99699699).

The spelling of 16509138 in words is "sixteen million, five hundred nine thousand, one hundred thirty-eight".