138966673561 has 2 divisors, whose sum is σ = 138966673562. Its totient is φ = 138966673560.

The previous prime is 138966673513. The next prime is 138966673567. The reversal of 138966673561 is 165376669831.

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., 104704663561 + 34262010000 = 323581^2 + 185100^2 .

It is an emirp because it is prime and its reverse (165376669831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138966673561 - 2¹⁵ = 138966640793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138966673561.

It is not a weakly prime, because it can be changed into another prime (138966673567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69483336780 + 69483336781.

It is an arithmetic number, because the mean of its divisors is an integer number (69483336781).

Almost surely, 2^138966673561 is an apocalyptic number.

It is an amenable number.

138966673561 is a deficient number, since it is larger than the sum of its proper divisors (1).

138966673561 is an equidigital number, since it uses as much as digits as its factorization.

138966673561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29393280, while the sum is 61.

The spelling of 138966673561 in words is "one hundred thirty-eight billion, nine hundred sixty-six million, six hundred seventy-three thousand, five hundred sixty-one".