27158765261 has 2 divisors, whose sum is σ = 27158765262. Its totient is φ = 27158765260.

The previous prime is 27158765251. The next prime is 27158765329. The reversal of 27158765261 is 16256785172.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26766923236 + 391842025 = 163606^2 + 19795^2 .

It is a cyclic number.

It is not a de Polignac number, because 27158765261 - 2²² = 27154570957 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27158765251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13579382630 + 13579382631.

It is an arithmetic number, because the mean of its divisors is an integer number (13579382631).

Almost surely, 2^27158765261 is an apocalyptic number.

It is an amenable number.

27158765261 is a deficient number, since it is larger than the sum of its proper divisors (1).

27158765261 is an equidigital number, since it uses as much as digits as its factorization.

27158765261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1411200, while the sum is 50.

The spelling of 27158765261 in words is "twenty-seven billion, one hundred fifty-eight million, seven hundred sixty-five thousand, two hundred sixty-one".