139239871 has 2 divisors, whose sum is σ = 139239872. Its totient is φ = 139239870.

The previous prime is 139239853. The next prime is 139239899. The reversal of 139239871 is 178932931.

139239871 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (178932931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139239871 - 2⁷ = 139239743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139239811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69619935 + 69619936.

It is an arithmetic number, because the mean of its divisors is an integer number (69619936).

Almost surely, 2^139239871 is an apocalyptic number.

139239871 is a deficient number, since it is larger than the sum of its proper divisors (1).

139239871 is an equidigital number, since it uses as much as digits as its factorization.

139239871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 43.

The square root of 139239871 is about 11799.9945338970. The cubic root of 139239871 is about 518.3079505864.

The spelling of 139239871 in words is "one hundred thirty-nine million, two hundred thirty-nine thousand, eight hundred seventy-one".