16138587818 has 16 divisors (see below), whose sum is σ = 24584227080. Its totient is φ = 7944708096.

The previous prime is 16138587791. The next prime is 16138587847. The reversal of 16138587818 is 81878583161.

It can be written as a sum of positive squares in 4 ways, for example, as 10505635009 + 5632952809 = 102497^2 + 75053^2 .

It is a super-2 number, since 2×16138587818² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178073 + ... + 252956.

Almost surely, 2^16138587818 is an apocalyptic number.

16138587818 is a deficient number, since it is larger than the sum of its proper divisors (8445639262).

16138587818 is a wasteful number, since it uses less digits than its factorization.

16138587818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431321.

The product of its digits is 2580480, while the sum is 56.

The spelling of 16138587818 in words is "sixteen billion, one hundred thirty-eight million, five hundred eighty-seven thousand, eight hundred eighteen".