138917641 has 2 divisors, whose sum is σ = 138917642. Its totient is φ = 138917640.

The previous prime is 138917621. The next prime is 138917651. The reversal of 138917641 is 146719831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107557641 + 31360000 = 10371^2 + 5600^2 .

It is an emirp because it is prime and its reverse (146719831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138917641 - 2¹⁵ = 138884873 is a prime.

It is a super-2 number, since 2×138917641² = 38596221962009762, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138917594 and 138917603.

It is not a weakly prime, because it can be changed into another prime (138917621) 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, 69458820 + 69458821.

It is an arithmetic number, because the mean of its divisors is an integer number (69458821).

Almost surely, 2^138917641 is an apocalyptic number.

It is an amenable number.

138917641 is a deficient number, since it is larger than the sum of its proper divisors (1).

138917641 is an equidigital number, since it uses as much as digits as its factorization.

138917641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 40.

The square root of 138917641 is about 11786.3328054149. The cubic root of 138917641 is about 517.9078176577.

The spelling of 138917641 in words is "one hundred thirty-eight million, nine hundred seventeen thousand, six hundred forty-one".