27380728261 has 2 divisors, whose sum is σ = 27380728262. Its totient is φ = 27380728260.

The previous prime is 27380728231. The next prime is 27380728267. The reversal of 27380728261 is 16282708372.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27355175236 + 25553025 = 165394^2 + 5055^2 .

It is a cyclic number.

It is not a de Polignac number, because 27380728261 - 2²¹ = 27378631109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27380728267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13690364130 + 13690364131.

It is an arithmetic number, because the mean of its divisors is an integer number (13690364131).

Almost surely, 2^27380728261 is an apocalyptic number.

It is an amenable number.

27380728261 is a deficient number, since it is larger than the sum of its proper divisors (1).

27380728261 is an equidigital number, since it uses as much as digits as its factorization.

27380728261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 451584, while the sum is 46.

The spelling of 27380728261 in words is "twenty-seven billion, three hundred eighty million, seven hundred twenty-eight thousand, two hundred sixty-one".