138909403 has 2 divisors, whose sum is σ = 138909404. Its totient is φ = 138909402.

The previous prime is 138909389. The next prime is 138909409. The reversal of 138909403 is 304909831.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138909403 is a prime.

It is not a weakly prime, because it can be changed into another prime (138909409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69454701 + 69454702.

It is an arithmetic number, because the mean of its divisors is an integer number (69454702).

Almost surely, 2^138909403 is an apocalyptic number.

138909403 is a deficient number, since it is larger than the sum of its proper divisors (1).

138909403 is an equidigital number, since it uses as much as digits as its factorization.

138909403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 138909403 is about 11785.9833276651. The cubic root of 138909403 is about 517.8975799156.

The spelling of 138909403 in words is "one hundred thirty-eight million, nine hundred nine thousand, four hundred three".