139157281 has 2 divisors, whose sum is σ = 139157282. Its totient is φ = 139157280.

The previous prime is 139157279. The next prime is 139157297. The reversal of 139157281 is 182751931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 139027681 + 129600 = 11791^2 + 360^2 .

It is an emirp because it is prime and its reverse (182751931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139157281 - 2¹ = 139157279 is a prime.

It is a super-2 number, since 2×139157281² = 38729497710625922, which contains 22 as substring.

Together with 139157279, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 139157281.

It is not a weakly prime, because it can be changed into another prime (139157201) 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, 69578640 + 69578641.

It is an arithmetic number, because the mean of its divisors is an integer number (69578641).

Almost surely, 2^139157281 is an apocalyptic number.

It is an amenable number.

139157281 is a deficient number, since it is larger than the sum of its proper divisors (1).

139157281 is an equidigital number, since it uses as much as digits as its factorization.

139157281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 37.

The square root of 139157281 is about 11796.4944369079. The cubic root of 139157281 is about 518.2054523585.

The spelling of 139157281 in words is "one hundred thirty-nine million, one hundred fifty-seven thousand, two hundred eighty-one".