27743281921 has 2 divisors, whose sum is σ = 27743281922. Its totient is φ = 27743281920.

The previous prime is 27743281901. The next prime is 27743281967. The reversal of 27743281921 is 12918234772.

It is an a-pointer prime, because the next prime (27743281967) can be obtained adding 27743281921 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22466712321 + 5276569600 = 149889^2 + 72640^2 .

It is a cyclic number.

It is not a de Polignac number, because 27743281921 - 2¹⁷ = 27743150849 is a prime.

It is not a weakly prime, because it can be changed into another prime (27743281901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13871640960 + 13871640961.

It is an arithmetic number, because the mean of its divisors is an integer number (13871640961).

Almost surely, 2^27743281921 is an apocalyptic number.

It is an amenable number.

27743281921 is a deficient number, since it is larger than the sum of its proper divisors (1).

27743281921 is an equidigital number, since it uses as much as digits as its factorization.

27743281921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 46.

The spelling of 27743281921 in words is "twenty-seven billion, seven hundred forty-three million, two hundred eighty-one thousand, nine hundred twenty-one".