27897464821 has 2 divisors, whose sum is σ = 27897464822. Its totient is φ = 27897464820.

The previous prime is 27897464813. The next prime is 27897464827. The reversal of 27897464821 is 12846479872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27884324196 + 13140625 = 166986^2 + 3625^2 .

It is a cyclic number.

It is not a de Polignac number, because 27897464821 - 2³ = 27897464813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27897464827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13948732410 + 13948732411.

It is an arithmetic number, because the mean of its divisors is an integer number (13948732411).

Almost surely, 2^27897464821 is an apocalyptic number.

It is an amenable number.

27897464821 is a deficient number, since it is larger than the sum of its proper divisors (1).

27897464821 is an equidigital number, since it uses as much as digits as its factorization.

27897464821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10838016, while the sum is 58.

The spelling of 27897464821 in words is "twenty-seven billion, eight hundred ninety-seven million, four hundred sixty-four thousand, eight hundred twenty-one".