138897637 has 2 divisors, whose sum is σ = 138897638. Its totient is φ = 138897636.

The previous prime is 138897589. The next prime is 138897641. The reversal of 138897637 is 736798831.

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., 134699236 + 4198401 = 11606^2 + 2049^2 .

It is a cyclic number.

It is not a de Polignac number, because 138897637 - 2⁷ = 138897509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138897677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69448818 + 69448819.

It is an arithmetic number, because the mean of its divisors is an integer number (69448819).

Almost surely, 2^138897637 is an apocalyptic number.

It is an amenable number.

138897637 is a deficient number, since it is larger than the sum of its proper divisors (1).

138897637 is an equidigital number, since it uses as much as digits as its factorization.

138897637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1524096, while the sum is 52.

The square root of 138897637 is about 11785.4841648530. The cubic root of 138897637 is about 517.8829570635.

The spelling of 138897637 in words is "one hundred thirty-eight million, eight hundred ninety-seven thousand, six hundred thirty-seven".