139405879 has 2 divisors, whose sum is σ = 139405880. Its totient is φ = 139405878.

The previous prime is 139405859. The next prime is 139405891. The reversal of 139405879 is 978504931.

It is a happy number.

139405879 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (978504931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139405879 - 2²¹ = 137308727 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139405859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69702939 + 69702940.

It is an arithmetic number, because the mean of its divisors is an integer number (69702940).

Almost surely, 2^139405879 is an apocalyptic number.

139405879 is a deficient number, since it is larger than the sum of its proper divisors (1).

139405879 is an equidigital number, since it uses as much as digits as its factorization.

139405879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 139405879 is about 11807.0266790585. The cubic root of 139405879 is about 518.5138520843.

The spelling of 139405879 in words is "one hundred thirty-nine million, four hundred five thousand, eight hundred seventy-nine".