138126491 has 2 divisors, whose sum is σ = 138126492. Its totient is φ = 138126490.

The previous prime is 138126481. The next prime is 138126557. The reversal of 138126491 is 194621831.

138126491 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 is a cyclic number.

It is not a de Polignac number, because 138126491 - 2¹⁰ = 138125467 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138126451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69063245 + 69063246.

It is an arithmetic number, because the mean of its divisors is an integer number (69063246).

Almost surely, 2^138126491 is an apocalyptic number.

138126491 is a deficient number, since it is larger than the sum of its proper divisors (1).

138126491 is an equidigital number, since it uses as much as digits as its factorization.

138126491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 35.

The square root of 138126491 is about 11752.7227058244. The cubic root of 138126491 is about 516.9227661802.

It can be divided in two parts, 1381 and 26491, that added together give a palindrome (27872).

The spelling of 138126491 in words is "one hundred thirty-eight million, one hundred twenty-six thousand, four hundred ninety-one".