138681469 has 2 divisors, whose sum is σ = 138681470. Its totient is φ = 138681468.

The previous prime is 138681391. The next prime is 138681481. The reversal of 138681469 is 964186831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 96924025 + 41757444 = 9845^2 + 6462^2 .

It is a cyclic number.

It is not a de Polignac number, because 138681469 - 2¹³ = 138673277 is a prime.

It is a super-2 number, since 2×138681469² = 38465099687995922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138681769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69340734 + 69340735.

It is an arithmetic number, because the mean of its divisors is an integer number (69340735).

Almost surely, 2^138681469 is an apocalyptic number.

It is an amenable number.

138681469 is a deficient number, since it is larger than the sum of its proper divisors (1).

138681469 is an equidigital number, since it uses as much as digits as its factorization.

138681469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 46.

The square root of 138681469 is about 11776.3096511598. The cubic root of 138681469 is about 517.6141551554.

The spelling of 138681469 in words is "one hundred thirty-eight million, six hundred eighty-one thousand, four hundred sixty-nine".