139694689 has 2 divisors, whose sum is σ = 139694690. Its totient is φ = 139694688.

The previous prime is 139694683. The next prime is 139694693. The reversal of 139694689 is 986496931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87609600 + 52085089 = 9360^2 + 7217^2 .

It is a cyclic number.

It is not a de Polignac number, because 139694689 - 2⁵ = 139694657 is a prime.

It is a super-4 number, since 4×139694689⁴ (a number of 34 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139694683) 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, 69847344 + 69847345.

It is an arithmetic number, because the mean of its divisors is an integer number (69847345).

Almost surely, 2^139694689 is an apocalyptic number.

It is an amenable number.

139694689 is a deficient number, since it is larger than the sum of its proper divisors (1).

139694689 is an equidigital number, since it uses as much as digits as its factorization.

139694689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2519424, while the sum is 55.

The square root of 139694689 is about 11819.2507799776. The cubic root of 139694689 is about 518.8716769977.

The spelling of 139694689 in words is "one hundred thirty-nine million, six hundred ninety-four thousand, six hundred eighty-nine".