139391069 has 2 divisors, whose sum is σ = 139391070. Its totient is φ = 139391068.

The previous prime is 139391047. The next prime is 139391071. The reversal of 139391069 is 960193931.

139391069 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130759225 + 8631844 = 11435^2 + 2938^2 .

It is an emirp because it is prime and its reverse (960193931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139391069 - 2¹⁶ = 139325533 is a prime.

It is a super-2 number, since 2×139391069² = 38859740233925522, which contains 22 as substring.

Together with 139391071, 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 (139391089) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69695534 + 69695535.

It is an arithmetic number, because the mean of its divisors is an integer number (69695535).

Almost surely, 2^139391069 is an apocalyptic number.

It is an amenable number.

139391069 is a deficient number, since it is larger than the sum of its proper divisors (1).

139391069 is an equidigital number, since it uses as much as digits as its factorization.

139391069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39366, while the sum is 41.

The square root of 139391069 is about 11806.3994934950. The cubic root of 139391069 is about 518.4954897260.

The spelling of 139391069 in words is "one hundred thirty-nine million, three hundred ninety-one thousand, sixty-nine".