139847861 has 2 divisors, whose sum is σ = 139847862. Its totient is φ = 139847860.

The previous prime is 139847857. The next prime is 139847879. The reversal of 139847861 is 168748931.

139847861 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., 112232836 + 27615025 = 10594^2 + 5255^2 .

It is a cyclic number.

It is not a de Polignac number, because 139847861 - 2² = 139847857 is a prime.

It is a Sophie Germain prime.

It is a Chen 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 (139847801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69923930 + 69923931.

It is an arithmetic number, because the mean of its divisors is an integer number (69923931).

Almost surely, 2^139847861 is an apocalyptic number.

It is an amenable number.

139847861 is a deficient number, since it is larger than the sum of its proper divisors (1).

139847861 is an equidigital number, since it uses as much as digits as its factorization.

139847861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 47.

The square root of 139847861 is about 11825.7287724690. The cubic root of 139847861 is about 519.0612513298.

The spelling of 139847861 in words is "one hundred thirty-nine million, eight hundred forty-seven thousand, eight hundred sixty-one".