139681349 has 4 divisors (see below), whose sum is σ = 139724460. Its totient is φ = 139638240.

The previous prime is 139681273. The next prime is 139681357. The reversal of 139681349 is 943186931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 943186931 = 113 ⋅8346787.

It can be written as a sum of positive squares in 2 ways, for example, as 49773025 + 89908324 = 7055^2 + 9482^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139681349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139680349) 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, 16262 + ... + 23319.

It is an arithmetic number, because the mean of its divisors is an integer number (34931115).

Almost surely, 2^139681349 is an apocalyptic number.

It is an amenable number.

139681349 is a deficient number, since it is larger than the sum of its proper divisors (43111).

139681349 is an equidigital number, since it uses as much as digits as its factorization.

139681349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43110.

The product of its digits is 139968, while the sum is 44.

The square root of 139681349 is about 11818.6864329332. The cubic root of 139681349 is about 518.8551601003.

The spelling of 139681349 in words is "one hundred thirty-nine million, six hundred eighty-one thousand, three hundred forty-nine".