138355217 has 32 divisors (see below), whose sum is σ = 187971840. Its totient is φ = 98334720.

The previous prime is 138355211. The next prime is 138355229. The reversal of 138355217 is 712553831.

It is not a de Polignac number, because 138355217 - 2⁸ = 138354961 is a prime.

It is a super-2 number, since 2×138355217² = 38284332142234178, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138355211) 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 31 ways as a sum of consecutive naturals, for example, 88313 + ... + 89865.

It is an arithmetic number, because the mean of its divisors is an integer number (5874120).

Almost surely, 2^138355217 is an apocalyptic number.

It is an amenable number.

138355217 is a deficient number, since it is larger than the sum of its proper divisors (49616623).

138355217 is a wasteful number, since it uses less digits than its factorization.

138355217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1673.

The product of its digits is 25200, while the sum is 35.

The square root of 138355217 is about 11762.4494472878. The cubic root of 138355217 is about 517.2079358920.

The spelling of 138355217 in words is "one hundred thirty-eight million, three hundred fifty-five thousand, two hundred seventeen".