138651224881 has 9 divisors (see below), whose sum is σ = 150142367019. Its totient is φ = 127981277736.

The previous prime is 138651224861. The next prime is 138651224893. The reversal of 138651224881 is 188422156831.

The square root of 138651224881 is 372359.

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

It can be written as a sum of positive squares in only one way, i.e., 20510536225 + 118140688656 = 143215^2 + 343716^2 .

It is not a de Polignac number, because 138651224881 - 2¹¹ = 138651222833 is a prime.

It is a super-2 number, since 2×138651224881² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138651224801) 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 in 8 ways as a sum of consecutive naturals, for example, 4826346 + ... + 4854988.

Almost surely, 2^138651224881 is an apocalyptic number.

138651224881 is the 372359-th square number.

138651224881 is the 186180-th centered octagonal number.

It is an amenable number.

138651224881 is a deficient number, since it is larger than the sum of its proper divisors (11491142138).

138651224881 is an frugal number, since it uses more digits than its factorization.

138651224881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57312 (or 28656 counting only the distinct ones).

The product of its digits is 737280, while the sum is 49.

Multiplying 138651224881 by its sum of digits (49), we get a square (6793910019169 = 2606513²).

The spelling of 138651224881 in words is "one hundred thirty-eight billion, six hundred fifty-one million, two hundred twenty-four thousand, eight hundred eighty-one".