138520004 has 12 divisors (see below), whose sum is σ = 277040064. Its totient is φ = 59365704.

The previous prime is 138520003. The next prime is 138520069. The reversal of 138520004 is 400025831.

138520004 is an admirable number.

It is a super-4 number, since 4×138520004⁴ (a number of 34 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (138520003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2473544 + ... + 2473599.

It is an arithmetic number, because the mean of its divisors is an integer number (23086672).

Almost surely, 2^138520004 is an apocalyptic number.

138520004 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

138520004 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

138520004 is a wasteful number, since it uses less digits than its factorization.

138520004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4947154 (or 4947152 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 138520004 is about 11769.4521537750. The cubic root of 138520004 is about 517.4131933714.

Adding to 138520004 its reverse (400025831), we get a palindrome (538545835).

The spelling of 138520004 in words is "one hundred thirty-eight million, five hundred twenty thousand, four".