138217805 has 8 divisors (see below), whose sum is σ = 180939744. Its totient is φ = 100522000.

The previous prime is 138217757. The next prime is 138217819. The reversal of 138217805 is 508712831.

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

It is not a de Polignac number, because 138217805 - 2²² = 134023501 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1256471 + ... + 1256580.

It is an arithmetic number, because the mean of its divisors is an integer number (22617468).

Almost surely, 2^138217805 is an apocalyptic number.

It is an amenable number.

138217805 is a deficient number, since it is larger than the sum of its proper divisors (42721939).

138217805 is a wasteful number, since it uses less digits than its factorization.

138217805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2513067.

The product of its (nonzero) digits is 13440, while the sum is 35.

The square root of 138217805 is about 11756.6068659286. The cubic root of 138217805 is about 517.0366518592.

The spelling of 138217805 in words is "one hundred thirty-eight million, two hundred seventeen thousand, eight hundred five".