138705520 has 40 divisors (see below), whose sum is σ = 323126640. Its totient is φ = 55372800.

The previous prime is 138705517. The next prime is 138705527. The reversal of 138705520 is 25507831.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138705527) 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 7 ways as a sum of consecutive naturals, for example, 48120 + ... + 50920.

It is an arithmetic number, because the mean of its divisors is an integer number (8078166).

Almost surely, 2^138705520 is an apocalyptic number.

138705520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138705520 is an abundant number, since it is smaller than the sum of its proper divisors (184421120).

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

138705520 is a wasteful number, since it uses less digits than its factorization.

138705520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3433 (or 3427 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 138705520 is about 11777.3307671985. The cubic root of 138705520 is about 517.6440760442.

The spelling of 138705520 in words is "one hundred thirty-eight million, seven hundred five thousand, five hundred twenty".