139307891 has 2 divisors, whose sum is σ = 139307892. Its totient is φ = 139307890.

The previous prime is 139307771. The next prime is 139307929. The reversal of 139307891 is 198703931.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 139307891 - 2¹⁸ = 139045747 is a prime.

It is not a weakly prime, because it can be changed into another prime (139307291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69653945 + 69653946.

It is an arithmetic number, because the mean of its divisors is an integer number (69653946).

Almost surely, 2^139307891 is an apocalyptic number.

139307891 is a deficient number, since it is larger than the sum of its proper divisors (1).

139307891 is an equidigital number, since it uses as much as digits as its factorization.

139307891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 139307891 is about 11802.8763867118. The cubic root of 139307891 is about 518.3923362997.

The spelling of 139307891 in words is "one hundred thirty-nine million, three hundred seven thousand, eight hundred ninety-one".