27996561 has 12 divisors (see below), whose sum is σ = 41203188. Its totient is φ = 18311904.

The previous prime is 27996559. The next prime is 27996587. The reversal of 27996561 is 16569972.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16646400 + 11350161 = 4080^2 + 3369^2 .

It is not a de Polignac number, because 27996561 - 2¹ = 27996559 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (27996961) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28870 + ... + 29823.

It is an arithmetic number, because the mean of its divisors is an integer number (3433599).

Almost surely, 2^27996561 is an apocalyptic number.

It is an amenable number.

27996561 is a deficient number, since it is larger than the sum of its proper divisors (13206627).

27996561 is a wasteful number, since it uses less digits than its factorization.

27996561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58752 (or 58749 counting only the distinct ones).

The product of its digits is 204120, while the sum is 45.

The square root of 27996561 is about 5291.1776571950. The cubic root of 27996561 is about 303.6464647387.

The spelling of 27996561 in words is "twenty-seven million, nine hundred ninety-six thousand, five hundred sixty-one".