139849609 has 2 divisors, whose sum is σ = 139849610. Its totient is φ = 139849608.

The previous prime is 139849607. The next prime is 139849621. The reversal of 139849609 is 906948931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128323584 + 11526025 = 11328^2 + 3395^2 .

It is a cyclic number.

It is not a de Polignac number, because 139849609 - 2¹ = 139849607 is a prime.

Together with 139849607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (139849607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69924804 + 69924805.

It is an arithmetic number, because the mean of its divisors is an integer number (69924805).

Almost surely, 2^139849609 is an apocalyptic number.

It is an amenable number.

139849609 is a deficient number, since it is larger than the sum of its proper divisors (1).

139849609 is an equidigital number, since it uses as much as digits as its factorization.

139849609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 49.

The square root of 139849609 is about 11825.8026788882. The cubic root of 139849609 is about 519.0634139544.

The spelling of 139849609 in words is "one hundred thirty-nine million, eight hundred forty-nine thousand, six hundred nine".