138151818 has 48 divisors (see below), whose sum is σ = 354768960. Its totient is φ = 39470976.

The previous prime is 138151817. The next prime is 138151859. The reversal of 138151818 is 818151831.

It is a happy number.

138151818 is a `hidden beast` number, since 138 + 1 + 518 + 1 + 8 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138151817) 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 23 ways as a sum of consecutive naturals, for example, 16903 + ... + 23706.

It is an arithmetic number, because the mean of its divisors is an integer number (7391020).

Almost surely, 2^138151818 is an apocalyptic number.

138151818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

138151818 is an abundant number, since it is smaller than the sum of its proper divisors (216617142).

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

138151818 is an equidigital number, since it uses as much as digits as its factorization.

138151818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40633 (or 40621 counting only the distinct ones).

The product of its digits is 7680, while the sum is 36.

The square root of 138151818 is about 11753.8001514404. The cubic root of 138151818 is about 516.9543587268.

The spelling of 138151818 in words is "one hundred thirty-eight million, one hundred fifty-one thousand, eight hundred eighteen".