139001909 has 2 divisors, whose sum is σ = 139001910. Its totient is φ = 139001908.

The previous prime is 139001879. The next prime is 139001917. The reversal of 139001909 is 909100931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108784900 + 30217009 = 10430^2 + 5497^2 .

It is a cyclic number.

It is not a de Polignac number, because 139001909 - 2²⁴ = 122224693 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139000909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69500954 + 69500955.

It is an arithmetic number, because the mean of its divisors is an integer number (69500955).

Almost surely, 2^139001909 is an apocalyptic number.

It is an amenable number.

139001909 is a deficient number, since it is larger than the sum of its proper divisors (1).

139001909 is an equidigital number, since it uses as much as digits as its factorization.

139001909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 139001909 is about 11789.9070819070. The cubic root of 139001909 is about 518.0125181453.

The spelling of 139001909 in words is "one hundred thirty-nine million, one thousand, nine hundred nine".