138199261 has 4 divisors (see below), whose sum is σ = 138257532. Its totient is φ = 138140992.

The previous prime is 138199253. The next prime is 138199279. The reversal of 138199261 is 162991831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35176761 + 103022500 = 5931^2 + 10150^2 .

It is a cyclic number.

It is not a de Polignac number, because 138199261 - 2³ = 138199253 is a prime.

It is a super-2 number, since 2×138199261² = 38198071481892242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138199211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25420 + ... + 30373.

It is an arithmetic number, because the mean of its divisors is an integer number (34564383).

Almost surely, 2^138199261 is an apocalyptic number.

It is an amenable number.

138199261 is a deficient number, since it is larger than the sum of its proper divisors (58271).

138199261 is an equidigital number, since it uses as much as digits as its factorization.

138199261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58270.

The product of its digits is 23328, while the sum is 40.

The square root of 138199261 is about 11755.8181765456. The cubic root of 138199261 is about 517.0135280740.

The spelling of 138199261 in words is "one hundred thirty-eight million, one hundred ninety-nine thousand, two hundred sixty-one".