65493781 has 2 divisors, whose sum is σ = 65493782. Its totient is φ = 65493780.

The previous prime is 65493761. The next prime is 65493797. The reversal of 65493781 is 18739456.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42693156 + 22800625 = 6534^2 + 4775^2 .

It is a cyclic number.

It is not a de Polignac number, because 65493781 - 2⁵ = 65493749 is a prime.

It is a super-2 number, since 2×65493781² = 8578870699351922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65493751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32746890 + 32746891.

It is an arithmetic number, because the mean of its divisors is an integer number (32746891).

Almost surely, 2^65493781 is an apocalyptic number.

It is an amenable number.

65493781 is a deficient number, since it is larger than the sum of its proper divisors (1).

65493781 is an equidigital number, since it uses as much as digits as its factorization.

65493781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 43.

The square root of 65493781 is about 8092.8228078959. The cubic root of 65493781 is about 403.0881408601.

The spelling of 65493781 in words is "sixty-five million, four hundred ninety-three thousand, seven hundred eighty-one".