139738649 has 2 divisors, whose sum is σ = 139738650. Its totient is φ = 139738648.

The previous prime is 139738583. The next prime is 139738663. The reversal of 139738649 is 946837931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 109411600 + 30327049 = 10460^2 + 5507^2 .

It is a cyclic number.

It is not a de Polignac number, because 139738649 - 2⁸ = 139738393 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 139738597 and 139738606.

It is not a weakly prime, because it can be changed into another prime (139728649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69869324 + 69869325.

It is an arithmetic number, because the mean of its divisors is an integer number (69869325).

Almost surely, 2^139738649 is an apocalyptic number.

It is an amenable number.

139738649 is a deficient number, since it is larger than the sum of its proper divisors (1).

139738649 is an equidigital number, since it uses as much as digits as its factorization.

139738649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 50.

The square root of 139738649 is about 11821.1103116416. The cubic root of 139738649 is about 518.9260985530.

It can be divided in two parts, 13973 and 8649, that added together give a palindrome (22622).

The spelling of 139738649 in words is "one hundred thirty-nine million, seven hundred thirty-eight thousand, six hundred forty-nine".