139681441 has 2 divisors, whose sum is σ = 139681442. Its totient is φ = 139681440.

The previous prime is 139681439. The next prime is 139681457. The reversal of 139681441 is 144186931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137710225 + 1971216 = 11735^2 + 1404^2 .

It is a cyclic number.

It is not a de Polignac number, because 139681441 - 2¹ = 139681439 is a prime.

Together with 139681439, it forms a pair of twin primes.

It is equal to p_7895161 and since 139681441 and 7895161 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 139681441.

It is not a weakly prime, because it can be changed into another prime (139681541) 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 as a sum of consecutive naturals, namely, 69840720 + 69840721.

It is an arithmetic number, because the mean of its divisors is an integer number (69840721).

Almost surely, 2^139681441 is an apocalyptic number.

It is an amenable number.

139681441 is a deficient number, since it is larger than the sum of its proper divisors (1).

139681441 is an equidigital number, since it uses as much as digits as its factorization.

139681441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 37.

The square root of 139681441 is about 11818.6903250741. The cubic root of 139681441 is about 518.8552740136.

The spelling of 139681441 in words is "one hundred thirty-nine million, six hundred eighty-one thousand, four hundred forty-one".