139091 has 2 divisors, whose sum is σ = 139092. Its totient is φ = 139090.

The previous prime is 139079. The next prime is 139109. The reversal of 139091 is 190931.

Together with next prime (139109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139091 is a prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 139091.

It is not a weakly prime, because it can be changed into another prime (139021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69545 + 69546.

It is an arithmetic number, because the mean of its divisors is an integer number (69546).

2¹³⁹⁰⁹¹ is an apocalyptic number.

139091 is a deficient number, since it is larger than the sum of its proper divisors (1).

139091 is an equidigital number, since it uses as much as digits as its factorization.

139091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 243, while the sum is 23.

The square root of 139091 is about 372.9490581836. The cubic root of 139091 is about 51.8123165060.

The spelling of 139091 in words is "one hundred thirty-nine thousand, ninety-one".