139185481 has 4 divisors (see below), whose sum is σ = 139227012. Its totient is φ = 139143952.

The previous prime is 139185463. The next prime is 139185491. The reversal of 139185481 is 184581931.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42458256 + 96727225 = 6516^2 + 9835^2 .

It is a cyclic number.

It is not a de Polignac number, because 139185481 - 2⁷ = 139185353 is a prime.

It is a super-2 number, since 2×139185481² = 38745196242402722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139185461) 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, 15250 + ... + 22603.

It is an arithmetic number, because the mean of its divisors is an integer number (34806753).

Almost surely, 2^139185481 is an apocalyptic number.

It is an amenable number.

139185481 is a deficient number, since it is larger than the sum of its proper divisors (41531).

139185481 is an equidigital number, since it uses as much as digits as its factorization.

139185481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41530.

The product of its digits is 34560, while the sum is 40.

The square root of 139185481 is about 11797.6896467063. The cubic root of 139185481 is about 518.2404544958.

The spelling of 139185481 in words is "one hundred thirty-nine million, one hundred eighty-five thousand, four hundred eighty-one".