65836721 has 2 divisors, whose sum is σ = 65836722. Its totient is φ = 65836720.

The previous prime is 65836703. The next prime is 65836747. The reversal of 65836721 is 12763856.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65788321 + 48400 = 8111^2 + 220^2 .

It is a cyclic number.

It is not a de Polignac number, because 65836721 - 2²² = 61642417 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (65836781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32918360 + 32918361.

It is an arithmetic number, because the mean of its divisors is an integer number (32918361).

Almost surely, 2^65836721 is an apocalyptic number.

It is an amenable number.

65836721 is a deficient number, since it is larger than the sum of its proper divisors (1).

65836721 is an equidigital number, since it uses as much as digits as its factorization.

65836721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 38.

The square root of 65836721 is about 8113.9830539631. The cubic root of 65836721 is about 403.7904694775.

The spelling of 65836721 in words is "sixty-five million, eight hundred thirty-six thousand, seven hundred twenty-one".