27647809421 has 2 divisors, whose sum is σ = 27647809422. Its totient is φ = 27647809420.

The previous prime is 27647809417. The next prime is 27647809477. The reversal of 27647809421 is 12490874672.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25512075625 + 2135733796 = 159725^2 + 46214^2 .

It is a cyclic number.

It is not a de Polignac number, because 27647809421 - 2² = 27647809417 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 27647809421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27641809421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13823904710 + 13823904711.

It is an arithmetic number, because the mean of its divisors is an integer number (13823904711).

Almost surely, 2^27647809421 is an apocalyptic number.

It is an amenable number.

27647809421 is a deficient number, since it is larger than the sum of its proper divisors (1).

27647809421 is an equidigital number, since it uses as much as digits as its factorization.

27647809421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1354752, while the sum is 50.

The spelling of 27647809421 in words is "twenty-seven billion, six hundred forty-seven million, eight hundred nine thousand, four hundred twenty-one".