27138938121 has 27 divisors (see below), whose sum is σ = 39710454901. Its totient is φ = 17860343424.

The previous prime is 27138938119. The next prime is 27138938129. The reversal of 27138938121 is 12183983172.

The square root of 27138938121 is 164739.

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

It can be written as a sum of positive squares in 4 ways, for example, as 17858313225 + 9280624896 = 133635^2 + 96336^2 .

It is not a de Polignac number, because 27138938121 - 2¹ = 27138938119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27138938129) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 43985005 + ... + 43985621.

Almost surely, 2^27138938121 is an apocalyptic number.

27138938121 is the 164739-th square number.

27138938121 is the 82370-th centered octagonal number.

It is an amenable number.

27138938121 is a deficient number, since it is larger than the sum of its proper divisors (12571516780).

27138938121 is an frugal number, since it uses more digits than its factorization.

27138938121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1418 (or 709 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The spelling of 27138938121 in words is "twenty-seven billion, one hundred thirty-eight million, nine hundred thirty-eight thousand, one hundred twenty-one".