138090217 has 2 divisors, whose sum is σ = 138090218. Its totient is φ = 138090216.

The previous prime is 138090193. The next prime is 138090259. The reversal of 138090217 is 712090831.

138090217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125014761 + 13075456 = 11181^2 + 3616^2 .

It is a cyclic number.

It is not a de Polignac number, because 138090217 - 2¹⁹ = 137565929 is a prime.

It is a super-2 number, since 2×138090217² = 38137816062214178, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (138090287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69045108 + 69045109.

It is an arithmetic number, because the mean of its divisors is an integer number (69045109).

Almost surely, 2^138090217 is an apocalyptic number.

It is an amenable number.

138090217 is a deficient number, since it is larger than the sum of its proper divisors (1).

138090217 is an equidigital number, since it uses as much as digits as its factorization.

138090217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 138090217 is about 11751.1793876189. The cubic root of 138090217 is about 516.8775117714.

The spelling of 138090217 in words is "one hundred thirty-eight million, ninety thousand, two hundred seventeen".