138991177 has 6 divisors (see below), whose sum is σ = 150505422. Its totient is φ = 128299392.

The previous prime is 138991163. The next prime is 138991199. The reversal of 138991177 is 771199831.

It can be written as a sum of positive squares in 3 ways, for example, as 13461561 + 125529616 = 3669^2 + 11204^2 .

It is not a de Polignac number, because 138991177 - 2¹¹ = 138989129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138991477) 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 in 5 ways as a sum of consecutive naturals, for example, 411048 + ... + 411385.

It is an arithmetic number, because the mean of its divisors is an integer number (25084237).

Almost surely, 2^138991177 is an apocalyptic number.

It is an amenable number.

138991177 is a deficient number, since it is larger than the sum of its proper divisors (11514245).

138991177 is an equidigital number, since it uses as much as digits as its factorization.

138991177 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822459 (or 822446 counting only the distinct ones).

The product of its digits is 95256, while the sum is 46.

The square root of 138991177 is about 11789.4519380674. The cubic root of 138991177 is about 517.9991863058. Note that the first 3 decimals are identical.

The spelling of 138991177 in words is "one hundred thirty-eight million, nine hundred ninety-one thousand, one hundred seventy-seven".