139935409 has 2 divisors, whose sum is σ = 139935410. Its totient is φ = 139935408.

The previous prime is 139935311. The next prime is 139935413. The reversal of 139935409 is 904539931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108743184 + 31192225 = 10428^2 + 5585^2 .

It is a cyclic number.

It is not a de Polignac number, because 139935409 - 2⁹ = 139934897 is a prime.

It is not a weakly prime, because it can be changed into another prime (139935709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69967704 + 69967705.

It is an arithmetic number, because the mean of its divisors is an integer number (69967705).

Almost surely, 2^139935409 is an apocalyptic number.

It is an amenable number.

139935409 is a deficient number, since it is larger than the sum of its proper divisors (1).

139935409 is an equidigital number, since it uses as much as digits as its factorization.

139935409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 131220, while the sum is 43.

The square root of 139935409 is about 11829.4297833835. The cubic root of 139935409 is about 519.1695435236.

The spelling of 139935409 in words is "one hundred thirty-nine million, nine hundred thirty-five thousand, four hundred nine".