27665400321 has 24 divisors (see below), whose sum is σ = 43096585896. Its totient is φ = 17000524800.

The previous prime is 27665400271. The next prime is 27665400403. The reversal of 27665400321 is 12300456672.

27665400321 is a `hidden beast` number, since 27 + 66 + 540 + 0 + 32 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3806273025 + 23859127296 = 61695^2 + 154464^2 .

It is not a de Polignac number, because 27665400321 - 2²¹ = 27663303169 is a prime.

It is not an unprimeable number, because it can be changed into a prime (27665400121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 86640 + ... + 250673.

It is an arithmetic number, because the mean of its divisors is an integer number (1795691079).

Almost surely, 2^27665400321 is an apocalyptic number.

It is an amenable number.

27665400321 is a deficient number, since it is larger than the sum of its proper divisors (15431185575).

27665400321 is a wasteful number, since it uses less digits than its factorization.

27665400321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338033 (or 338030 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

Adding to 27665400321 its reverse (12300456672), we get a palindrome (39965856993).

The spelling of 27665400321 in words is "twenty-seven billion, six hundred sixty-five million, four hundred thousand, three hundred twenty-one".