138635669 has 2 divisors, whose sum is σ = 138635670. Its totient is φ = 138635668.

The previous prime is 138635641. The next prime is 138635677. The reversal of 138635669 is 966536831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137710225 + 925444 = 11735^2 + 962^2 .

It is a cyclic number.

It is not a de Polignac number, because 138635669 - 2¹² = 138631573 is a prime.

It is a super-2 number, since 2×138635669² = 38439697438155122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138635269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69317834 + 69317835.

It is an arithmetic number, because the mean of its divisors is an integer number (69317835).

Almost surely, 2^138635669 is an apocalyptic number.

It is an amenable number.

138635669 is a deficient number, since it is larger than the sum of its proper divisors (1).

138635669 is an equidigital number, since it uses as much as digits as its factorization.

138635669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 47.

The square root of 138635669 is about 11774.3649085630. The cubic root of 138635669 is about 517.5571676365.

The spelling of 138635669 in words is "one hundred thirty-eight million, six hundred thirty-five thousand, six hundred sixty-nine".