139021871 has 2 divisors, whose sum is σ = 139021872. Its totient is φ = 139021870.

The previous prime is 139021859. The next prime is 139021873. The reversal of 139021871 is 178120931.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 139021871 - 2⁶ = 139021807 is a prime.

Together with 139021873, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139021873) 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, 69510935 + 69510936.

It is an arithmetic number, because the mean of its divisors is an integer number (69510936).

Almost surely, 2^139021871 is an apocalyptic number.

139021871 is a deficient number, since it is larger than the sum of its proper divisors (1).

139021871 is an equidigital number, since it uses as much as digits as its factorization.

139021871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 139021871 is about 11790.7536230726. The cubic root of 139021871 is about 518.0373141379.

The spelling of 139021871 in words is "one hundred thirty-nine million, twenty-one thousand, eight hundred seventy-one".