139605491 has 2 divisors, whose sum is σ = 139605492. Its totient is φ = 139605490.

The previous prime is 139605457. The next prime is 139605497. The reversal of 139605491 is 194506931.

139605491 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 a cyclic number.

It is not a de Polignac number, because 139605491 - 2²² = 135411187 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139605497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69802745 + 69802746.

It is an arithmetic number, because the mean of its divisors is an integer number (69802746).

Almost surely, 2^139605491 is an apocalyptic number.

139605491 is a deficient number, since it is larger than the sum of its proper divisors (1).

139605491 is an equidigital number, since it uses as much as digits as its factorization.

139605491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 139605491 is about 11815.4767572028. The cubic root of 139605491 is about 518.7612166540.

The spelling of 139605491 in words is "one hundred thirty-nine million, six hundred five thousand, four hundred ninety-one".