138805261 has 8 divisors (see below), whose sum is σ = 159776960. Its totient is φ = 118119168.

The previous prime is 138805237. The next prime is 138805267. The reversal of 138805261 is 162508831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138805261 - 2⁹ = 138804749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138805267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70356 + ... + 72301.

It is an arithmetic number, because the mean of its divisors is an integer number (19972120).

Almost surely, 2^138805261 is an apocalyptic number.

It is an amenable number.

138805261 is a deficient number, since it is larger than the sum of its proper divisors (20971699).

138805261 is a wasteful number, since it uses less digits than its factorization.

138805261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142803.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 138805261 is about 11781.5644546894. The cubic root of 138805261 is about 517.7681229392.

The spelling of 138805261 in words is "one hundred thirty-eight million, eight hundred five thousand, two hundred sixty-one".