139281893 has 2 divisors, whose sum is σ = 139281894. Its totient is φ = 139281892.

The previous prime is 139281823. The next prime is 139281917. The reversal of 139281893 is 398182931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74269924 + 65011969 = 8618^2 + 8063^2 .

It is an emirp because it is prime and its reverse (398182931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139281893 - 2¹² = 139277797 is a prime.

It is equal to p_7873766 and since 139281893 and 7873766 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139281823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69640946 + 69640947.

It is an arithmetic number, because the mean of its divisors is an integer number (69640947).

Almost surely, 2^139281893 is an apocalyptic number.

It is an amenable number.

139281893 is a deficient number, since it is larger than the sum of its proper divisors (1).

139281893 is an equidigital number, since it uses as much as digits as its factorization.

139281893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 44.

The square root of 139281893 is about 11801.7749936185. The cubic root of 139281893 is about 518.3600863859.

The spelling of 139281893 in words is "one hundred thirty-nine million, two hundred eighty-one thousand, eight hundred ninety-three".