139773281 has 2 divisors, whose sum is σ = 139773282. Its totient is φ = 139773280.

The previous prime is 139773259. The next prime is 139773287. The reversal of 139773281 is 182377931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124099600 + 15673681 = 11140^2 + 3959^2 .

It is an emirp because it is prime and its reverse (182377931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139773281 - 2¹⁸ = 139511137 is a prime.

It is a super-2 number, since 2×139773281² = 39073140163009922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (139773287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69886640 + 69886641.

It is an arithmetic number, because the mean of its divisors is an integer number (69886641).

Almost surely, 2^139773281 is an apocalyptic number.

It is an amenable number.

139773281 is a deficient number, since it is larger than the sum of its proper divisors (1).

139773281 is an equidigital number, since it uses as much as digits as its factorization.

139773281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63504, while the sum is 41.

The square root of 139773281 is about 11822.5750579136. The cubic root of 139773281 is about 518.9689642033.

The spelling of 139773281 in words is "one hundred thirty-nine million, seven hundred seventy-three thousand, two hundred eighty-one".