39855139 has 2 divisors, whose sum is σ = 39855140. Its totient is φ = 39855138.

The previous prime is 39855133. The next prime is 39855163. The reversal of 39855139 is 93155893.

It is a weak prime.

It is an emirp because it is prime and its reverse (93155893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39855139 - 2³ = 39855131 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 39855095 and 39855104.

It is not a weakly prime, because it can be changed into another prime (39855131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19927569 + 19927570.

It is an arithmetic number, because the mean of its divisors is an integer number (19927570).

Almost surely, 2^39855139 is an apocalyptic number.

39855139 is a deficient number, since it is larger than the sum of its proper divisors (1).

39855139 is an equidigital number, since it uses as much as digits as its factorization.

39855139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145800, while the sum is 43.

The square root of 39855139 is about 6313.0926652474. The cubic root of 39855139 is about 341.5818419077.

The spelling of 39855139 in words is "thirty-nine million, eight hundred fifty-five thousand, one hundred thirty-nine".