139687813 has 2 divisors, whose sum is σ = 139687814. Its totient is φ = 139687812.

The previous prime is 139687811. The next prime is 139687819. The reversal of 139687813 is 318786931.

139687813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99960004 + 39727809 = 9998^2 + 6303^2 .

It is a cyclic number.

It is not a de Polignac number, because 139687813 - 2¹ = 139687811 is a prime.

Together with 139687811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139687811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69843906 + 69843907.

It is an arithmetic number, because the mean of its divisors is an integer number (69843907).

Almost surely, 2^139687813 is an apocalyptic number.

It is an amenable number.

139687813 is a deficient number, since it is larger than the sum of its proper divisors (1).

139687813 is an equidigital number, since it uses as much as digits as its factorization.

139687813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 46.

The square root of 139687813 is about 11818.9598950161. The cubic root of 139687813 is about 518.8631636218.

The spelling of 139687813 in words is "one hundred thirty-nine million, six hundred eighty-seven thousand, eight hundred thirteen".