26783632781 has 2 divisors, whose sum is σ = 26783632782. Its totient is φ = 26783632780.

The previous prime is 26783632763. The next prime is 26783632801. The reversal of 26783632781 is 18723638762.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15341051881 + 11442580900 = 123859^2 + 106970^2 .

It is a cyclic number.

It is not a de Polignac number, because 26783632781 - 2⁶ = 26783632717 is a prime.

It is a super-2 number, since 2×26783632781² (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 (26783632721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13391816390 + 13391816391.

It is an arithmetic number, because the mean of its divisors is an integer number (13391816391).

Almost surely, 2^26783632781 is an apocalyptic number.

It is an amenable number.

26783632781 is a deficient number, since it is larger than the sum of its proper divisors (1).

26783632781 is an equidigital number, since it uses as much as digits as its factorization.

26783632781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4064256, while the sum is 53.

The spelling of 26783632781 in words is "twenty-six billion, seven hundred eighty-three million, six hundred thirty-two thousand, seven hundred eighty-one".