138806169489 has 81 divisors (see below), whose sum is σ = 223490703891. Its totient is φ = 82978122240.

The previous prime is 138806169487. The next prime is 138806169493. The reversal of 138806169489 is 984961608831.

The square root of 138806169489 is 372567.

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

138806169489 is a `hidden beast` number, since 1 + 3 + 8 + 8 + 0 + 616 + 9 + 4 + 8 + 9 = 666.

It can be written as a sum of positive squares in 13 ways, for example, as 108383833089 + 30422336400 = 329217^2 + 174420^2 .

It is not a de Polignac number, because 138806169489 - 2¹ = 138806169487 is a prime.

It is a super-2 number, since 2×138806169489² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138806169487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 595734517 + ... + 595734749.

Almost surely, 2^138806169489 is an apocalyptic number.

138806169489 is the 372567-th square number.

138806169489 is the 186284-th centered octagonal number.

It is an amenable number.

138806169489 is a deficient number, since it is larger than the sum of its proper divisors (84684534402).

138806169489 is an equidigital number, since it uses as much as digits as its factorization.

138806169489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 17915904, while the sum is 63.

The spelling of 138806169489 in words is "one hundred thirty-eight billion, eight hundred six million, one hundred sixty-nine thousand, four hundred eighty-nine".