138696641 has 2 divisors, whose sum is σ = 138696642. Its totient is φ = 138696640.

The previous prime is 138696619. The next prime is 138696661. The reversal of 138696641 is 146696831.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128482225 + 10214416 = 11335^2 + 3196^2 .

It is a cyclic number.

It is not a de Polignac number, because 138696641 - 2¹⁴ = 138680257 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 138696592 and 138696601.

It is not a weakly prime, because it can be changed into another prime (138696611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69348320 + 69348321.

It is an arithmetic number, because the mean of its divisors is an integer number (69348321).

Almost surely, 2^138696641 is an apocalyptic number.

It is an amenable number.

138696641 is a deficient number, since it is larger than the sum of its proper divisors (1).

138696641 is an equidigital number, since it uses as much as digits as its factorization.

138696641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 44.

The square root of 138696641 is about 11776.9538081798. The cubic root of 138696641 is about 517.6330304376.

The spelling of 138696641 in words is "one hundred thirty-eight million, six hundred ninety-six thousand, six hundred forty-one".