139626281 has 2 divisors, whose sum is σ = 139626282. Its totient is φ = 139626280.

The previous prime is 139626239. The next prime is 139626283. The reversal of 139626281 is 182626931.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94400656 + 45225625 = 9716^2 + 6725^2 .

It is a cyclic number.

It is not a de Polignac number, because 139626281 - 2²² = 135431977 is a prime.

It is a super-2 number, since 2×139626281² = 38990996691781922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 139626283, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (139626283) 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, 69813140 + 69813141.

It is an arithmetic number, because the mean of its divisors is an integer number (69813141).

Almost surely, 2^139626281 is an apocalyptic number.

It is an amenable number.

139626281 is a deficient number, since it is larger than the sum of its proper divisors (1).

139626281 is an equidigital number, since it uses as much as digits as its factorization.

139626281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 38.

The square root of 139626281 is about 11816.3565027465. The cubic root of 139626281 is about 518.7869666210.

The spelling of 139626281 in words is "one hundred thirty-nine million, six hundred twenty-six thousand, two hundred eighty-one".