27780444917 has 2 divisors, whose sum is σ = 27780444918. Its totient is φ = 27780444916.

The previous prime is 27780444803. The next prime is 27780444973. The reversal of 27780444917 is 71944408772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19056698116 + 8723746801 = 138046^2 + 93401^2 .

It is a cyclic number.

It is not a de Polignac number, because 27780444917 - 2³² = 23485477621 is a prime.

It is a super-2 number, since 2×27780444917² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27780434917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13890222458 + 13890222459.

It is an arithmetic number, because the mean of its divisors is an integer number (13890222459).

Almost surely, 2^27780444917 is an apocalyptic number.

It is an amenable number.

27780444917 is a deficient number, since it is larger than the sum of its proper divisors (1).

27780444917 is an equidigital number, since it uses as much as digits as its factorization.

27780444917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3161088, while the sum is 53.

The spelling of 27780444917 in words is "twenty-seven billion, seven hundred eighty million, four hundred forty-four thousand, nine hundred seventeen".