138908851 has 2 divisors, whose sum is σ = 138908852. Its totient is φ = 138908850.

The previous prime is 138908843. The next prime is 138908857. The reversal of 138908851 is 158809831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138908851 - 2³ = 138908843 is a prime.

It is a super-2 number, since 2×138908851² = 38591337772280402, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138908798 and 138908807.

It is not a weakly prime, because it can be changed into another prime (138908857) 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, 69454425 + 69454426.

It is an arithmetic number, because the mean of its divisors is an integer number (69454426).

Almost surely, 2^138908851 is an apocalyptic number.

138908851 is a deficient number, since it is larger than the sum of its proper divisors (1).

138908851 is an equidigital number, since it uses as much as digits as its factorization.

138908851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 43.

The square root of 138908851 is about 11785.9599099946. The cubic root of 138908851 is about 517.8968939053.

The spelling of 138908851 in words is "one hundred thirty-eight million, nine hundred eight thousand, eight hundred fifty-one".