138343261 has 4 divisors (see below), whose sum is σ = 158106592. Its totient is φ = 118579932.

The previous prime is 138343241. The next prime is 138343267. The reversal of 138343261 is 162343831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 138343261 - 2¹¹ = 138341213 is a prime.

It is a super-2 number, since 2×138343261² = 38277715728228242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138343267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9881655 + ... + 9881668.

It is an arithmetic number, because the mean of its divisors is an integer number (39526648).

Almost surely, 2^138343261 is an apocalyptic number.

It is an amenable number.

138343261 is a deficient number, since it is larger than the sum of its proper divisors (19763331).

138343261 is an equidigital number, since it uses as much as digits as its factorization.

138343261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19763330.

The product of its digits is 10368, while the sum is 31.

The square root of 138343261 is about 11761.9412088311. The cubic root of 138343261 is about 517.1930372460.

It can be divided in two parts, 1383 and 43261, that added together give a palindrome (44644).

The spelling of 138343261 in words is "one hundred thirty-eight million, three hundred forty-three thousand, two hundred sixty-one".