139217609 has 2 divisors, whose sum is σ = 139217610. Its totient is φ = 139217608.

The previous prime is 139217557. The next prime is 139217629. The reversal of 139217609 is 906712931.

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., 139169209 + 48400 = 11797^2 + 220^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139217609 is a prime.

It is equal to p_7870358 and since 139217609 and 7870358 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (139217629) 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, 69608804 + 69608805.

It is an arithmetic number, because the mean of its divisors is an integer number (69608805).

Almost surely, 2^139217609 is an apocalyptic number.

It is an amenable number.

139217609 is a deficient number, since it is larger than the sum of its proper divisors (1).

139217609 is an equidigital number, since it uses as much as digits as its factorization.

139217609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20412, while the sum is 38.

The square root of 139217609 is about 11799.0511906678. The cubic root of 139217609 is about 518.2803263470.

The spelling of 139217609 in words is "one hundred thirty-nine million, two hundred seventeen thousand, six hundred nine".