27616781 has 2 divisors, whose sum is σ = 27616782. Its totient is φ = 27616780.

The previous prime is 27616751. The next prime is 27616783. The reversal of 27616781 is 18761672.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18062500 + 9554281 = 4250^2 + 3091^2 .

It is a cyclic number.

It is not a de Polignac number, because 27616781 - 2⁶ = 27616717 is a prime.

It is a super-2 number, since 2×27616781² = 1525373185603922, which contains 22 as substring.

Together with 27616783, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27616783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13808390 + 13808391.

It is an arithmetic number, because the mean of its divisors is an integer number (13808391).

Almost surely, 2^27616781 is an apocalyptic number.

It is an amenable number.

27616781 is a deficient number, since it is larger than the sum of its proper divisors (1).

27616781 is an equidigital number, since it uses as much as digits as its factorization.

27616781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 38.

The square root of 27616781 is about 5255.1670763164. The cubic root of 27616781 is about 302.2671969715.

The spelling of 27616781 in words is "twenty-seven million, six hundred sixteen thousand, seven hundred eighty-one".