27891464813 has 2 divisors, whose sum is σ = 27891464814. Its totient is φ = 27891464812.

The previous prime is 27891464771. The next prime is 27891464833. The reversal of 27891464813 is 31846419872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24931778404 + 2959686409 = 157898^2 + 54403^2 .

It is a cyclic number.

It is not a de Polignac number, because 27891464813 - 2²⁰ = 27890416237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27891464833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13945732406 + 13945732407.

It is an arithmetic number, because the mean of its divisors is an integer number (13945732407).

Almost surely, 2^27891464813 is an apocalyptic number.

It is an amenable number.

27891464813 is a deficient number, since it is larger than the sum of its proper divisors (1).

27891464813 is an equidigital number, since it uses as much as digits as its factorization.

27891464813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2322432, while the sum is 53.

The spelling of 27891464813 in words is "twenty-seven billion, eight hundred ninety-one million, four hundred sixty-four thousand, eight hundred thirteen".