27731950781 has 2 divisors, whose sum is σ = 27731950782. Its totient is φ = 27731950780.

The previous prime is 27731950769. The next prime is 27731950837. The reversal of 27731950781 is 18705913772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14196722500 + 13535228281 = 119150^2 + 116341^2 .

It is a cyclic number.

It is not a de Polignac number, because 27731950781 - 2¹⁴ = 27731934397 is a prime.

It is a super-2 number, since 2×27731950781² (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 (27731970781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13865975390 + 13865975391.

It is an arithmetic number, because the mean of its divisors is an integer number (13865975391).

Almost surely, 2^27731950781 is an apocalyptic number.

It is an amenable number.

27731950781 is a deficient number, since it is larger than the sum of its proper divisors (1).

27731950781 is an equidigital number, since it uses as much as digits as its factorization.

27731950781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 740880, while the sum is 50.

The spelling of 27731950781 in words is "twenty-seven billion, seven hundred thirty-one million, nine hundred fifty thousand, seven hundred eighty-one".