139978913 has 2 divisors, whose sum is σ = 139978914. Its totient is φ = 139978912.

The previous prime is 139978873. The next prime is 139978939. The reversal of 139978913 is 319879931.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87459904 + 52519009 = 9352^2 + 7247^2 .

It is a cyclic number.

It is not a de Polignac number, because 139978913 - 2¹⁰ = 139977889 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (139978313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69989456 + 69989457.

It is an arithmetic number, because the mean of its divisors is an integer number (69989457).

Almost surely, 2^139978913 is an apocalyptic number.

It is an amenable number.

139978913 is a deficient number, since it is larger than the sum of its proper divisors (1).

139978913 is an equidigital number, since it uses as much as digits as its factorization.

139978913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 50.

The square root of 139978913 is about 11831.2684442540. The cubic root of 139978913 is about 519.2233388468.

The spelling of 139978913 in words is "one hundred thirty-nine million, nine hundred seventy-eight thousand, nine hundred thirteen".