138041640 has 144 divisors (see below), whose sum is σ = 493283700. Its totient is φ = 33454080.

The previous prime is 138041623. The next prime is 138041671. The reversal of 138041640 is 46140831.

138041640 is a `hidden beast` number, since 13 + 8 + 0 + 4 + 1 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 136469124 + 1572516 = 11682^2 + 1254^2 .

It is an unprimeable number.

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, 41976 + ... + 45144.

Almost surely, 2^138041640 is an apocalyptic number.

138041640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138041640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (246641850).

138041640 is an abundant number, since it is smaller than the sum of its proper divisors (355242060).

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

138041640 is a wasteful number, since it uses less digits than its factorization.

138041640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3208 (or 3190 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 138041640 is about 11749.1123068937. The cubic root of 138041640 is about 516.8168960759.

The spelling of 138041640 in words is "one hundred thirty-eight million, forty-one thousand, six hundred forty".