27431561 has 2 divisors, whose sum is σ = 27431562. Its totient is φ = 27431560.

The previous prime is 27431543. The next prime is 27431567. The reversal of 27431561 is 16513472.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27237961 + 193600 = 5219^2 + 440^2 .

It is a cyclic number.

It is not a de Polignac number, because 27431561 - 2¹⁴ = 27415177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (27431567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13715780 + 13715781.

It is an arithmetic number, because the mean of its divisors is an integer number (13715781).

Almost surely, 2^27431561 is an apocalyptic number.

It is an amenable number.

27431561 is a deficient number, since it is larger than the sum of its proper divisors (1).

27431561 is an equidigital number, since it uses as much as digits as its factorization.

27431561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 29.

The square root of 27431561 is about 5237.5147732489. The cubic root of 27431561 is about 301.5899328995.

The spelling of 27431561 in words is "twenty-seven million, four hundred thirty-one thousand, five hundred sixty-one".