138948749 has 2 divisors, whose sum is σ = 138948750. Its totient is φ = 138948748.

The previous prime is 138948739. The next prime is 138948757. The reversal of 138948749 is 947849831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138815524 + 133225 = 11782^2 + 365^2 .

It is a cyclic number.

It is not a de Polignac number, because 138948749 - 2⁸ = 138948493 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138948749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138948739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69474374 + 69474375.

It is an arithmetic number, because the mean of its divisors is an integer number (69474375).

Almost surely, 2^138948749 is an apocalyptic number.

It is an amenable number.

138948749 is a deficient number, since it is larger than the sum of its proper divisors (1).

138948749 is an equidigital number, since it uses as much as digits as its factorization.

138948749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 53.

The square root of 138948749 is about 11787.6523956214. The cubic root of 138948749 is about 517.9464733528.

The spelling of 138948749 in words is "one hundred thirty-eight million, nine hundred forty-eight thousand, seven hundred forty-nine".