138461621773 has 2 divisors, whose sum is σ = 138461621774. Its totient is φ = 138461621772.

The previous prime is 138461621759. The next prime is 138461621783. The reversal of 138461621773 is 377126164831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126623528964 + 11838092809 = 355842^2 + 108803^2 .

It is a cyclic number.

It is not a de Polignac number, because 138461621773 - 2²⁹ = 137924750861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138461621783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69230810886 + 69230810887.

It is an arithmetic number, because the mean of its divisors is an integer number (69230810887).

Almost surely, 2^138461621773 is an apocalyptic number.

It is an amenable number.

138461621773 is a deficient number, since it is larger than the sum of its proper divisors (1).

138461621773 is an equidigital number, since it uses as much as digits as its factorization.

138461621773 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 49.

The spelling of 138461621773 in words is "one hundred thirty-eight billion, four hundred sixty-one million, six hundred twenty-one thousand, seven hundred seventy-three".