27162665721 has 27 divisors (see below), whose sum is σ = 39622246573. Its totient is φ = 17931436800.

The previous prime is 27162665711. The next prime is 27162665779. The reversal of 27162665721 is 12756626172.

The square root of 27162665721 is 164811.

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

27162665721 is a `hidden beast` number, since 2 + 7 + 16 + 2 + 66 + 572 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 13253765625 + 13908900096 = 115125^2 + 117936^2 .

It is not a de Polignac number, because 27162665721 - 2¹⁷ = 27162534649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27162665711) 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 26 ways as a sum of consecutive naturals, for example, 67737121 + ... + 67737521.

Almost surely, 2^27162665721 is an apocalyptic number.

27162665721 is the 164811-st square number.

27162665721 is the 82406-th centered octagonal number.

It is an amenable number.

27162665721 is a deficient number, since it is larger than the sum of its proper divisors (12459580852).

27162665721 is an frugal number, since it uses more digits than its factorization.

27162665721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1082 (or 541 counting only the distinct ones).

The product of its digits is 423360, while the sum is 45.

The spelling of 27162665721 in words is "twenty-seven billion, one hundred sixty-two million, six hundred sixty-five thousand, seven hundred twenty-one".