138548931203761 has 75 divisors (see below), whose sum is σ = 160139518793763. Its totient is φ = 119868848686080.

The previous prime is 138548931203731. The next prime is 138548931203779. The reversal of 138548931203761 is 167302139845831.

The square root of 138548931203761 is 11770681.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 37 ways, for example, as 79470645866161 + 59078285337600 = 8914631^2 + 7686240^2 .

It is not a de Polignac number, because 138548931203761 - 2³⁵ = 138514571465393 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138548931203761.

It is not an unprimeable number, because it can be changed into a prime (138548931203731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 574891830601 + ... + 574891830841.

It is a 1-persistent number, because it is pandigital, but 2⋅138548931203761 = 277097862407522 is not.

Almost surely, 2^{138548931203761} is an apocalyptic number.

138548931203761 is the 11770681-st square number.

138548931203761 is the 5885341-st centered octagonal number.

It is an amenable number.

138548931203761 is a deficient number, since it is larger than the sum of its proper divisors (21590587590002).

138548931203761 is an frugal number, since it uses more digits than its factorization.

138548931203761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 26127360, while the sum is 61.

The spelling of 138548931203761 in words is "one hundred thirty-eight trillion, five hundred forty-eight billion, nine hundred thirty-one million, two hundred three thousand, seven hundred sixty-one".