139908491 has 2 divisors, whose sum is σ = 139908492. Its totient is φ = 139908490.

The previous prime is 139908481. The next prime is 139908493. The reversal of 139908491 is 194809931.

139908491 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 139908491 - 2¹⁴ = 139892107 is a prime.

Together with 139908493, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139908493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69954245 + 69954246.

It is an arithmetic number, because the mean of its divisors is an integer number (69954246).

Almost surely, 2^139908491 is an apocalyptic number.

139908491 is a deficient number, since it is larger than the sum of its proper divisors (1).

139908491 is an equidigital number, since it uses as much as digits as its factorization.

139908491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 139908491 is about 11828.2919730619. The cubic root of 139908491 is about 519.1362522071.

The spelling of 139908491 in words is "one hundred thirty-nine million, nine hundred eight thousand, four hundred ninety-one".