139617857 has 2 divisors, whose sum is σ = 139617858. Its totient is φ = 139617856.

The previous prime is 139617853. The next prime is 139617899. The reversal of 139617857 is 758716931.

It is a Cunningham number, because it is equal to 11816²+1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 139617856 + 1 = 11816^2 + 1^2 .

It is a cyclic number.

It is not a de Polignac number, because 139617857 - 2² = 139617853 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139617851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69808928 + 69808929.

It is an arithmetic number, because the mean of its divisors is an integer number (69808929).

Almost surely, 2^139617857 is an apocalyptic number.

It is an amenable number.

139617857 is a deficient number, since it is larger than the sum of its proper divisors (1).

139617857 is an equidigital number, since it uses as much as digits as its factorization.

139617857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 317520, while the sum is 47.

The square root of 139617857 is about 11816.0000423155. Note that the first 4 decimals coincide. The cubic root of 139617857 is about 518.7765331762.

The spelling of 139617857 in words is "one hundred thirty-nine million, six hundred seventeen thousand, eight hundred fifty-seven".