139690897 has 2 divisors, whose sum is σ = 139690898. Its totient is φ = 139690896.

The previous prime is 139690879. The next prime is 139690949. The reversal of 139690897 is 798096931.

Together with previous prime (139690879) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (139690949) can be obtained adding 139690897 to its sum of digits (52).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137733696 + 1957201 = 11736^2 + 1399^2 .

It is an emirp because it is prime and its reverse (798096931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139690897 - 2⁷ = 139690769 is a prime.

It is not a weakly prime, because it can be changed into another prime (139690847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69845448 + 69845449.

It is an arithmetic number, because the mean of its divisors is an integer number (69845449).

Almost surely, 2^139690897 is an apocalyptic number.

It is an amenable number.

139690897 is a deficient number, since it is larger than the sum of its proper divisors (1).

139690897 is an equidigital number, since it uses as much as digits as its factorization.

139690897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 734832, while the sum is 52.

The square root of 139690897 is about 11819.0903626294. The cubic root of 139690897 is about 518.8669820466.

The spelling of 139690897 in words is "one hundred thirty-nine million, six hundred ninety thousand, eight hundred ninety-seven".