138995557 has 2 divisors, whose sum is σ = 138995558. Its totient is φ = 138995556.

The previous prime is 138995539. The next prime is 138995567. The reversal of 138995557 is 755599831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77545636 + 61449921 = 8806^2 + 7839^2 .

It is a cyclic number.

It is not a de Polignac number, because 138995557 - 2⁷ = 138995429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138995567) 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, 69497778 + 69497779.

It is an arithmetic number, because the mean of its divisors is an integer number (69497779).

Almost surely, 2^138995557 is an apocalyptic number.

It is an amenable number.

138995557 is a deficient number, since it is larger than the sum of its proper divisors (1).

138995557 is an equidigital number, since it uses as much as digits as its factorization.

138995557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1701000, while the sum is 52.

The square root of 138995557 is about 11789.6376958751. The cubic root of 138995557 is about 518.0046274488.

The spelling of 138995557 in words is "one hundred thirty-eight million, nine hundred ninety-five thousand, five hundred fifty-seven".