139291 has 2 divisors, whose sum is σ = 139292. Its totient is φ = 139290.

The previous prime is 139273. The next prime is 139297. The reversal of 139291 is 192931.

It is a strong prime.

It is an emirp because it is prime and its reverse (192931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139291 - 2¹⁷ = 8219 is a prime.

It is not a weakly prime, because it can be changed into another prime (139297) 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, 69645 + 69646.

It is an arithmetic number, because the mean of its divisors is an integer number (69646).

2¹³⁹²⁹¹ is an apocalyptic number.

139291 is a deficient number, since it is larger than the sum of its proper divisors (1).

139291 is an equidigital number, since it uses as much as digits as its factorization.

139291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 486, while the sum is 25.

The square root of 139291 is about 373.2170949997. The cubic root of 139291 is about 51.8371383864.

The spelling of 139291 in words is "one hundred thirty-nine thousand, two hundred ninety-one".