139257817 has 2 divisors, whose sum is σ = 139257818. Its totient is φ = 139257816.

The previous prime is 139257773. The next prime is 139257823. The reversal of 139257817 is 718752931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138039001 + 1218816 = 11749^2 + 1104^2 .

It is a cyclic number.

It is not a de Polignac number, because 139257817 - 2²³ = 130869209 is a prime.

It is not a weakly prime, because it can be changed into another prime (139257857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69628908 + 69628909.

It is an arithmetic number, because the mean of its divisors is an integer number (69628909).

Almost surely, 2^139257817 is an apocalyptic number.

It is an amenable number.

139257817 is a deficient number, since it is larger than the sum of its proper divisors (1).

139257817 is an equidigital number, since it uses as much as digits as its factorization.

139257817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 105840, while the sum is 43.

The square root of 139257817 is about 11800.7549334778. The cubic root of 139257817 is about 518.3302170891.

The spelling of 139257817 in words is "one hundred thirty-nine million, two hundred fifty-seven thousand, eight hundred seventeen".