139261 has 4 divisors (see below), whose sum is σ = 142272. Its totient is φ = 136252.

The previous prime is 139241. The next prime is 139267. The reversal of 139261 is 162931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 162931 = 61 ⋅2671.

It is a cyclic number.

It is not a de Polignac number, because 139261 - 2⁷ = 139133 is a prime.

It is a super-2 number, since 2×139261² = 38787252242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139267) 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 in 3 ways as a sum of consecutive naturals, for example, 1435 + ... + 1528.

It is an arithmetic number, because the mean of its divisors is an integer number (35568).

2¹³⁹²⁶¹ is an apocalyptic number.

It is an amenable number.

139261 is a deficient number, since it is larger than the sum of its proper divisors (3011).

139261 is an equidigital number, since it uses as much as digits as its factorization.

139261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3010.

The product of its digits is 324, while the sum is 22.

The square root of 139261 is about 373.1769017504. The cubic root of 139261 is about 51.8334166197.

It can be divided in two parts, 139 and 261, that added together give a square (400 = 20²).

The spelling of 139261 in words is "one hundred thirty-nine thousand, two hundred sixty-one".