27802426781 has 2 divisors, whose sum is σ = 27802426782. Its totient is φ = 27802426780.

The previous prime is 27802426763. The next prime is 27802426789. The reversal of 27802426781 is 18762420872.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21895120900 + 5907305881 = 147970^2 + 76859^2 .

It is a cyclic number.

It is not a de Polignac number, because 27802426781 - 2¹⁴ = 27802410397 is a prime.

It is a super-2 number, since 2×27802426781² (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 (27802426789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13901213390 + 13901213391.

It is an arithmetic number, because the mean of its divisors is an integer number (13901213391).

Almost surely, 2^27802426781 is an apocalyptic number.

It is an amenable number.

27802426781 is a deficient number, since it is larger than the sum of its proper divisors (1).

27802426781 is an equidigital number, since it uses as much as digits as its factorization.

27802426781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 602112, while the sum is 47.

The spelling of 27802426781 in words is "twenty-seven billion, eight hundred two million, four hundred twenty-six thousand, seven hundred eighty-one".