27251990261 has 2 divisors, whose sum is σ = 27251990262. Its totient is φ = 27251990260.

The previous prime is 27251990257. The next prime is 27251990281. The reversal of 27251990261 is 16209915272.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23992151236 + 3259839025 = 154894^2 + 57095^2 .

It is a cyclic number.

It is not a de Polignac number, because 27251990261 - 2² = 27251990257 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27251990281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13625995130 + 13625995131.

It is an arithmetic number, because the mean of its divisors is an integer number (13625995131).

Almost surely, 2^27251990261 is an apocalyptic number.

It is an amenable number.

27251990261 is a deficient number, since it is larger than the sum of its proper divisors (1).

27251990261 is an equidigital number, since it uses as much as digits as its factorization.

27251990261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 136080, while the sum is 44.

The spelling of 27251990261 in words is "twenty-seven billion, two hundred fifty-one million, nine hundred ninety thousand, two hundred sixty-one".