65135821 has 2 divisors, whose sum is σ = 65135822. Its totient is φ = 65135820.

The previous prime is 65135803. The next prime is 65135869. The reversal of 65135821 is 12853156.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47073321 + 18062500 = 6861^2 + 4250^2 .

It is a cyclic number.

It is not a de Polignac number, because 65135821 - 2¹⁵ = 65103053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65135801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32567910 + 32567911.

It is an arithmetic number, because the mean of its divisors is an integer number (32567911).

Almost surely, 2^65135821 is an apocalyptic number.

It is an amenable number.

65135821 is a deficient number, since it is larger than the sum of its proper divisors (1).

65135821 is an equidigital number, since it uses as much as digits as its factorization.

65135821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 31.

The square root of 65135821 is about 8070.6766135188. The cubic root of 65135821 is about 402.3524317904.

Adding to 65135821 its reverse (12853156), we get a palindrome (77988977).

It can be divided in two parts, 65135 and 821, that added together give a palindrome (65956).

The spelling of 65135821 in words is "sixty-five million, one hundred thirty-five thousand, eight hundred twenty-one".