138944789 has 2 divisors, whose sum is σ = 138944790. Its totient is φ = 138944788.

The previous prime is 138944783. The next prime is 138944797. The reversal of 138944789 is 987449831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138886225 + 58564 = 11785^2 + 242^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138944789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138944789.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138944783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69472394 + 69472395.

It is an arithmetic number, because the mean of its divisors is an integer number (69472395).

Almost surely, 2^138944789 is an apocalyptic number.

It is an amenable number.

138944789 is a deficient number, since it is larger than the sum of its proper divisors (1).

138944789 is an equidigital number, since it uses as much as digits as its factorization.

138944789 is an evil number, because the sum of its binary digits is even.

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

The square root of 138944789 is about 11787.4844220470. The cubic root of 138944789 is about 517.9415528635.

The spelling of 138944789 in words is "one hundred thirty-eight million, nine hundred forty-four thousand, seven hundred eighty-nine".